An anti-terrorism unit is on the hunt for two suspects who left the UK on the night of the killing of Dr Imran Farooq.
On September 16, 2010, Mr Farooq was leaving work in Green Lane, Edgware, when he was attacked outside his office, dying of multiple stab wounds and blunt trauma to the head with the attackers using a kitchen knife and a house brick.
Detectives from the Metropolitan Police Counter Terrorism Command today named two men, 29-year-old Moshin Ali Syed and Muhammad Kashif Khan Kamran, 34, who they believe are involved in the murder and were living in Stanmore at the time.
The investigation into the murder was relaunched on the third anniversary of the killing.
Authorities believe the men are now based in their home nation of Pakistan, where Farooq was a senior member of the MQM party before moving to London in 1999.
Syed was based in the Harrow borough between February 2010 and September 16 2010, while Kamran was only in the country in the days leading up to the attack, with both men leaving the country on the evening of the murder.
The men are known to have registered to study at a college in East London having entered the UK on student visas.
Officers believe Dr Farooq's murder would have required detailed planning and assistance from a wider group of people, some of whom may have provided assistance or information unknowingly.
A spokesman for the Metropolitan police said: "We are appealing to anyone who has not yet come forward but knew either man in Pakistan or during their time in the UK to contact the investigation team.
"In particular, officers are keen to piece together the men's movements in the days immediately prior to the murder and their travel out of the UK on September 16 2010."
Officers continue to liaise with Pakistani authorities in tracing the men's whereabouts.
A 52-year-old man arrested in June 2013 on suspicion of conspiracy to murder at Heathrow airport when landing after a flight from Canada remains on police bail pending further enquiries.
Anyone who can assist should call the police incident room on 020 7230 2717 or contact the police by email at SO15Mailbox-.DrFarooqMurder@met.police.uk.
Anyone who wishes to remain anonymous can call Crimestoppers on 0800 555111 within the UK or use the Crimestoppers untraceable online form to pass on information at www.crimestoppers-uk.org.
