British police investigating the 2010 murder of Pakistani politician Imran Farooq said Monday they had arrested a man in connection with the case after he arrived in London on a flight from Canada.
Counter-terrorism detectives arrested the 52-year-old man at Heathrow Airport at 10.10 am (0910 GMT) and took him to a police station in London.
Farooq, 50, a founding member of the Muttahida Qaumi Movement (MQM), was stabbed and beaten to death in London as he returned home from work in September 2010.
Earlier this month, police searched two residential properties in London as part of the investigation.
Police have offered a reward of £20,000 ($30,700, 23,500 euros) for information that helps lead to a prosecution.
Police said the attack "would have required careful planning and would have required help from other people, some of whom may have provided assistance or information unwittingly".