A New Jersey transgender man has been fired after his employers decided that he did not fulfil a men-only requirement of the job.

El’Jai Devoureau, 39, was hired by a drug treatment centre last summer and was required to watch men giving urine samples for drug testing.

Close supervision is deemed necessary to ensure that urine samples are fresh and subjects do not try to cheat tests. Firms are permitted to specify employees’ gender for this type of work.

Mr Devoureau, who has had hormone treatment and surgery, was born female. He says he has lived as a man for decades and felt male since the age of five.

He said that after he was confronted about his gender by his bosses at Urban Treatment Associates, he was sacked on his second day in the job.

In a lawsuit, he says that the centre fired him after an acquaintance saw him at work and informed his bosses he was born biologically female.

Mr Devoureau is represented by the Transgender Legal Defense and Education Fund, which says almost half of trans people have been fired or denied promotions for being trans.

The group’s executive director Michael Silverman said: “This lawsuit challenges the discriminatory view that transgender men cannot work as men.

“El’Jai was qualified for the job and he performed it without complaint or incident. What matters in the workplace is how you do your job, not who you are.”

Mr Devoureau said: “I needed this job to support myself and my family. In this economy, jobs are really hard to find. They were happy to have me work there until they heard about my transition. I’m a hard worker and it’s unfair that I was fired over something that has nothing to do with how well I did the job.”

Urban Treatment Associates has not commented on the lawsuit. Last year it said Mr Devoureau was fired because he was not biologically male. The company denies discrimination.

New Jersey has a state-wide ban on anti-trans discrimination.