A U.N. team of experts says it saw a secret torture center inside a Sri Lankan navy base where many post-civil war detainees were believed to have been kept.  

Three experts from a U.N. working group on enforced disappearances are visiting Sri Lanka. Team member Ariel Dulitzk said Wednesday that "interrogation and torture took place" inside underground cells at the center in eastern Sri Lanka.

"We believe it's an important discovery and it should be properly investigated," he added.

Navy chief vice admiral Ravi Wijegunaratne said there was no torture center in the base.

The war ended in 2009 when the government defeated the Tamil Tiger rebels. The U.N. team says writing on the walls of the cells suggests people may have been detained there secretly until 2010.