For nearly 20 years, the Commonwealth operated under the mistaken assumption that it was allowed to hold people in immigration detention indefinitely. In 2023, the High Court’s landmark ruling confirmed otherwise.

We are now about to see the fallout of those events, with the government facing potential civil liability to people who, as it turns out, were unlawfully detained.

A new High Court judgment in a case called Abdel-Hady vs the Commonwealth has left the door open for a man who was unlawfully detained to sue the government for compensation, potentially allowing hundreds of others to do the same.

How did we get here?

The legal history traces back to a 2004 High Court case. That case found that the Migration Act allows the government to detain unlawful non-citizens until they were deported, even if there was no realistic prospect of deportation (for example, if no other country would accept them).

For a person who had nowhere else to go, this effectively led to indefinite detention.

In a 2023 decision, often dubbed the NZYQ case, the High Court reopened and overruled that earlier case on constitutional grounds. The upshot was that the government had, for some time, been relying on an invalid law to detain a person where there was no foreseeable prospect of deporting them.

Without legal authority to detain, the Commonwealth faces potential liability for false imprisonment. This tort (a civil wrong) provides compensation if a person, including a government official, detains someone without lawful authority.

It is relatively clear that people held in immigration detention have been “detained” in the legal sense. Since the NZYQ case, it also seems relatively clear that this detention was unlawful if there was no realistic prospect of deportation.

What did the court find?

This is where the new decision becomes relevant.

Safwat Abdel-Hady came to Australia from Austria in 1997. He lived here on a visa until it was cancelled on character grounds in 2017, leading to his detention. He commenced proceedings in 2021 challenging the legality of his detention and seeking compensation.

Abdel-Hady has a health condition that makes it dangerous for him to fly. The Commonwealth eventually came to accept that, from at least July 2022, there was no foreseeable prospect of deporting him. He was released in 2024 after the Commonwealth consented to court orders which ruled his detention for that period had been unlawful.

This left just the civil part of Abdel-Hady’s claim unresolved. With no real dispute about whether he had been unlawfully detained, the Commonwealth asked the High Court to recognise a new type of defence that would protect the government from liability.

In essence, the government argued that if an official is carrying out their duties under a law that’s previously been found to be valid, that would be a legal defence, even if the High Court later reverses its position.

All members of the High Court gave short shrift to that argument. One of the difficulties, the court said, was that the scope of the defence was ill-conceived.

More importantly, the defence did not sit comfortably with constitutional principle. The court reiterated that it’s a fundamental principle of our legal system that the government only interferes with liberty where it has legal authority to do so.

To recognise this new defence would have essentially transformed the government’s obligation to obey the law into an immunity where the government believes (even for good reason) it is acting within its power. Three judges said this “would amount to an inversion, if not a perversion, of constitutional principle”.

Potentially hundreds of claims

In rejecting the government’s defence, the judgment opens the door for Abdel-Hady and other people in a similar position to proceed with liability claims against the government.

Reports suggest around 350 people were released in the wake of the NZYQ finding. It is unclear how many of these people were actually detained unlawfully, or how many additional people might now be able to bring a claim.

Assuming any of these people are found to have been falsely imprisoned, the scope of potential liability will depend on each person’s circumstances, including the length of their detention and its impacts on them.

Previous false imprisonment claims against government have ranged from very significant awards in the order of hundreds of thousands of dollars all the way down to nominal damages of $1 in situations where detention was inevitable.

It is also possible that the Commonwealth will seek to settle claims rather than litigate, as it has done in previous false imprisonment matters in immigration detention.

Where to from here?

The implications of the High Court overruling its previous judgment in this situation are clearly significant for the government. The High Court only rarely overturns its previous judgments, and there are very important constitutional reasons why the High Court needs the ability to do so.

For the government, the matter may be an expensive lesson on the risks inherent in passing legislation that gives wide-ranging detention powers to the executive. Later regulatory workarounds have also been challenged and struck down.

As the High Court observed in this case, it was (and remains) open to government to manage or ameliorate some of those risks through carefully crafted legislation.

The case highlights the difficult position that government officials face when seeking to enforce a law that they believe to be valid, but later turns out not to be. But as Justice Michelle Gordon observed, to excuse the government from liability in this case on grounds of unfairness would simply shift the burden from the government to the unlawfully imprisoned person.

Ellen Rock is affiliated with the New South Wales Legislative Council Delegated Legislation Committee as an independent legal adviser.

The Sex Discrimination Act is currently in the news following the outcome of a high-profile court case reaffirming transgender rights in Australia.

The controversy concerns the meaning of “sex” in the act and its interaction with gender identity discrimination. The Coalition wants to amend the act to include a definition of biological sex, arguing “the law does not properly protect single sex spaces for women and girls”.

But what’s missing from the conversation is how the Sex Discrimination Act works and what it was designed to achieve.

What is the Sex Discrimination Act?

The Sex Discrimination Act is a federal law. It originally became law in 1984 and protected people from sex, pregnancy and marital status discrimination.

Currently, the act protects people from discrimination based on a wider range of attributes, called “protected attributes”. These include their sex, sexual orientation, gender identity, intersex status, marital or relationship status, pregnancy or potential pregnancy status, breastfeeding or family responsibilities.

Discrimination is prohibited in employment, the provision of goods, services and facilities, education, accommodation, land, clubs, and federal programs and laws. A purpose of the act is to eliminate “so far as possible” discrimination based on the protected attributes.

Unlawful discrimination is either “direct” or “indirect”. Direct discrimination occurs when a person with an attribute is treated less favourably than a person without that attribute in the same situation. Classic examples of direct sex discrimination are where a woman is paid less than a man while completing the same work.

Indirect discrimination addresses more subtle forms of inequality. For example, a rule may seem to treat everyone equally, but, in practice, it disadvantages one group that shares an attribute.

Let’s say a firm requires all partners to work a 60-hour week. People with family responsibilities could be less able to comply with this rule.

Rules that cause disadvantage based on an attribute can be legal if they are reasonable, but direct discrimination cannot be defended on the basis it is reasonable.

Read more: Politics with Michelle Grattan: Margaret Thornton on the landmark Tickle v Giggle transgender case

What are the exceptions?

There are limits to protection against discrimination under the Sex Discrimination Act.

The act contains many exceptions allowing conduct that would otherwise be discriminatory. For example, there are general exceptions for services where they can only be provided to members of one sex.

Exceptions also apply to staff and students in religious educational institutions.

There are exceptions for participation in sports where strength, stamina or physique is relevant.

It is also not discrimination to provide affirmative action or equal opportunity measures. But these exceptions, called “special measures”, cannot discriminate on the basis of other protected attributes.

Very few court tests

Despite the act being in force for more than 40 years, it has received little attention from higher courts.

The recent decision of Giggle For Girls v Tickle was the first case of gender identity discrimination heard by the Federal Court. The full bench found a transgender woman had been directly discriminated against on the basis of gender by being refused access to a women-only social media app.

The High Court of Australia has considered only three sex discrimination claims in its history. None of these was made under the Sex Discrimination Act. Two of those were decided in the 1980s, and one was considered in 2006. That means the High Court has not heard a sex discrimination claim in 20 years.

It has never considered the act and its prohibitions on discrimination. This means there is little higher court authority on how its provisions operate.

Read more: A historic court victory has upheld transgender rights in Australia. A legal academic explains why

The 2013 changes

Until 2013, federal law did not protect people from discrimination because of gender identity, sexual orientation or intersex status. While there were protections in state and territory acts for these attributes, they varied greatly. This led to inconsistent protection from discrimination across Australia.

In 2013, the federal Sex Discrimination Act was amended to include the attributes of gender identity, sexual orientation, intersex status and relationship status.

This made it unlawful to discriminate, directly or indirectly, against people based on their sexual orientation, gender identity, intersex status or relationship status. This protection from discrimination applies in all areas of life captured by the act.

The amendments created definitions of these newly protected attributes. The definition of gender identity was designed to achieve “maximum protection” for gender-diverse people.

It was also designed to recognise that “gender” and “sex” are distinct concepts. The definition indicates both are changeable.

Further, the definition of “intersex status” was designed to recognise that sex is not binary.

The definitions of “man” and “woman” were also removed and are instead understood by their “normal meaning”. This means the words aren’t narrowly interpreted to exclude transgender people. Women and men (of all ages) would also continue to be protected from discrimination based on their sex.

In 2013, the amendments made to the Sex Discrimination Act were not particularly controversial. As then-Attorney-General Mark Dreyfus noted in respect of a Senate Committee Report on human rights and discrimination legislation:

all parties agree on one issue – the pressing need for protection from discrimination for the lesbian, gay, bisexual, transgender and intersex community at the federal level.

It was recognised that there was substantial evidence of discrimination due to sexual orientation, gender identity and intersex status. This discrimination was harmful and created barriers in how people could live their lives.

While controversies have sprung up since, the 2013 changes to the Sex Discrimination Act remain a milestone. For many Australians, the changes marked the first time that federal law protected their right to live free from discrimination.

Alice Taylor does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.