Arrests have been made in connection with the murder subject to a four-year investigation by the metropolitan police.
This morning officers raided an address in Waltham Forest and arrested a man who remains in police custody.
The murder of Dr Imran Farooq took place on September 2010, when the 50-year-old man was on his way home from work.
It is believed that he was attacked outside his home in Green Lane, Edgware, and died as a result of multiple stab wounds and blunt trauma to the head.
A five-and-a-half inch bladed kitchen knife and a house brick used in the attack were recovered at the scene.
Detectives from the Metropolitan Police Service’s Counter Terrorism Command believe that Dr Farooq was under surveillance in the days and weeks prior to his murder.
This is not the first arrest made in connection with the murder, and police have already issued a statement in May this year requesting to speak to Moshin Ali Syed, 29, and Muhammad Kashif Khan Kamran, 35.
Both are believed to currently reside in Pakistan.
A 52-year-old man arrested in June 2013 on suspicion of conspiracy to murder remains on police bail pending further enquiries.
He is next due to return to a London police station on a date in late October.
Anyone who can assist should call the police incident room on +44 (0)20 7230 2717 or contact the police by email at SO15Mailbox-.DrFarooqMurder@met.police.uk.
Alternatively anyone who wishes to remain anonymous can call Crimestoppers, a charity independent of the police, on 0800 555 111 within the UK or use the Crimestoppers untraceable online form to pass on information at www.crimestoppers-uk.org.