Scotland Yard said officers detained a 34-year-old man at his home in the north London neighborhood of Camden for questioning.

“He has been taken to a north London police station where he will be interviewed by detectives,” the police headquarters said.

The man, who was not identified, was also being questioned on suspicion of robbery, police said.

The 50-year-old Farooq was on his way home from work when he was killed in broad daylight on Sept. 16. He was found with head injuries and stab wounds outside his London home and pronounced dead at the scene. Detectives recovered a kitchen knife and a brick used in the attack.

Detectives from Scotland Yard's counter-terrorism command have taken charge of the murder inquiry due to fears that the killing may be politically motivated. The suspect was also arrested for involvement in an October 2009 robbery.

“Detectives believe there are other people who may hold vital information about the attack and continue to urge them to come forward,” Scotland Yard said.

“They still want to trace two men and speak to them in connection with the incident.”

Both men were of “Asian appearance”, in their 20s or 30s with short, dark hair. One was of stocky build, the other slim, they said.

Farooq had been living in self-imposed exile in London since fleeing Pakistan in 1992.

He had twice been elected an MP in Pakistan but went into hiding in 1992 when the government ordered a military crackdown against party activists in Karachi.

He was a member of the Muttahida Qaumi Movement (MQM), one of Pakistan's major parties and the largest in the coalition governing his hometown of Karachi. The city erupted into violence at the news of his death.

An MQM leader had said the party believed Farooq was killed in response to controversial statements made by the leader of party, Altaf Hussain, who himself lives in London.

The party represents mainly descendants of Urdu-speaking migrants from India who settled in Pakistan when it was created in 1947.