Leading footwear retailer Foot Locker Inc is being sued by a former employee who claims he was fired for complaining about anti-gay harassment in the workplace.

According to the lawsuit, filed in a state court in South Carolina, 26-year-old Kevin Dunbar faced constant harassment over his sexuality at the hands of co-workers despite Foot Locker's anti-discrimination policy.

Dunbar, the suit alleges, complained to Foot Locker management under the promise that his grievance would be kept confidential.

However, after being transferred from one store to another, Dunbar's new manager allegedly knew of the situation and dismissed him on the grounds of his sexuality.

"When I took a job at Foot Locker, I looked at the policies and took comfort in knowing that the company was fair to gay employees," Dunbar said in a statement released by Lambda Legal, his representative in the suit.

"Since the policies were so clear, I never thought this would happen."

Foot Locker spokesman Bruce Hartman said he was unaware of the lawsuit, but promised his company would not tolerate discrimination.

"Our policy mentions everything," Hartman said.

"It's not just limited to gay people.

"It's not a practice our company would support or encourage."

The suit claims three customers witnessed separate incidents of anti-gay harassment at Foot Locker.