ISLAMABAD -- Pakistan's anti-corruption body says it has arrested the speaker of a provincial assembly and member of an opposition party headed by former President Asif Ali Zardari.

In Wednesday's statement, the National Accountability Bureau says Sindh Assembly Speaker Agha Siraj Durrani was arrested in the capital, Islamabad, on charges of "possessing assets beyond his known sources."

The anti-graft body has arrested several politicians and businessmen on corruption charges since Prime Minister Imran Khan took office last year following the removal of Nawaz Sharif by the country's top court over corruption allegations.

Durrani is a member of the Pakistan People's Party. Its leader, former President Zardari, faces a multimillion-dollar money laundering case opened last year, and is currently out on bail.