One of New York’s most prestigious law firms is being sued for discrimination on the grounds of sexual orientation by one of their own lawyers.

28-year-old associate Aaron B Charney says in his suit that senior colleagues subjected him to “lewd and illegal conduct,” The New York Times reports.

Sullivan Cromwell, founded in 1879, is one of America’s best known – and profitable – law firms.

It is particularly reknowned for its work on mergers and acquisitions, and it is this department that is the focus of the lawsuit.

While secretarial and other staff have sued law firms in the past for harassment, as an associate lawyer in his fourth year at the firm, Mr Charney is an unusual claimant.

The legal action could have a negative impact on his future career.

“The day I derailed my career was the day I complained about the discrimination,” he told the Times.

He added that he will be representing himself in court as no other lawyer is willing to take on Sullivan Cromwell.

Mr Charney wants a jury trial and is asking for undisclosed damages.

He alleges that he was the victim of discrimination and retaliation.

A senior colleague accused him of having a sexual relationship with a fellow employee and demanded he be fired. Mr Charney denies the relationship was sexual.

His boss also alluded to the alleged relationship, telling Mr Charney to put an end to it. He also alleges he was subject to sexually suggestive behaviour by partners.

The chairman of Sullivan Maxwell released an email statement to The New York Times denying the accusations.