Pakistan's interior minister says security forces have arrested a key suspect in the slaying of a prominent Pakistani politician who was stabbed to death in broad daylight in London in 2010.

The slain politician, Imran Farooq, was a senior leader of the Muttahida Qaumi Movement, one of Pakistan's main political parties. The MQM has been accused by opponents of using violence to bolster its power.

Interior Minister Chaudhry Nisar Ali Khan identified the suspect as Moazzam Ali.

He said Wednesday that Ali was arrested in the port city of Karachi, where MQM is headquartered.

Khan says Pakistan is questioning the suspect and will share its findings with British authorities, who are also pursuing the case.