The case is similar to one scheduled to go to trial later this month.

Employment visas are a politically charged topic in the United States, especially those related to Indian IT services companies that are seen as taking jobs away from Americans. The issue is especially sensitive in a presidential election year.

Satya Dev Tripuraneni, an American ex-employee, said he was harassed by his supervisor after he accused Infosys of visa fraud, according to the lawsuit filed on August 2 in the federal court for the Northern District of California.

"Shortly after Mr. Tripuraneni filed his complaint with the Infosys whistleblower team, per our policy, the company launched a comprehensive investigation of his allegations. That investigation is continuing," Infosys said in a statement emailed to Reuters.

"As for comments on the legal matter, we are choosing to concentrate our attention and resources on the investigation," it added.

Tripuraneni says Infosys billed clients fraudulently for workers brought from India and also charged clients for taxes over and above the required charge, according to the lawsuit.

The lawsuit follows one by another U.S. employee who said he suffered retaliation after pointing out what he said was the misuse of U.S. B1 visas.

That case, brought by Jack Palmer, an employee in Montgomery, Alabama, against the Bangalore-based company, is scheduled to go to trial on August 20. Infosys has denied any wrongdoing in the case.

B1 visas allow companies to send their employees to the United States for short-term business purposes.

Earlier this year, Infosys said it was being investigated in Texas over its sponsorship and use of short-term U.S. business visas.

(Editing by Tony Munroe, Jon Loades-Carter and Mark Potter)

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