The 51-year-old, whose provocative cartoons were deemed critical of the Palestinian regime when they appeared in Kuwaiti newspaper Al-Qabas, died on 29 August that year in hospital from his injuries.
Witnesses at the time said Mr Al-Ali was pursued for around 40 seconds by the suspected gunman before he was shot in the back of his neck.
Detectives said the decision to re-investigate the case was partly down to a possible shift in allegiances from those who may have known the identity of Mr Al-Ali's killer, as well as a second suspect who was later seen driving away from the scene.
Dean Haydon, head of the Metropolitan Police's counter terrorism command, said: “The brutal murder of Mr Al-Ali devastated his family and 30 years on they continue to feel the loss.
“We have previously reviewed this case and followed a number of lines of inquiry which have not resulted in us identifying these two men.
“However, a lot can change in 30 years - allegiances shift and people who were not willing to speak at the time of the murder may now be prepared to come forward with crucial information.
“We remain open-minded about the motive for Mr Al-Ali's murder and we believe there are people somewhere who have information that could help us bring those responsible for his murder to justice.”
In the moments leading up to Mr Al-Ali's murder, he parked his car on Ixworth Place, walked down into Draycott Avenue and onto Ives Street.
Witnesses reported seeing him being followed by the suspected gunman, who they described as being of Middle-Eastern appearance and aged about 25, with collar-length thick black hair that was wavy at the back. He was wearing a stonewashed denim jacket and dark trousers, police said.
Witnesses described seeing the suspect close to Mr Al-Ali, holding a black automatic handgun.
A witness reported seeing another man - also of Middle-Eastern appearance - crossing Fulham Road into Lucan Place and getting into the driver's seat of a silver-grey left-hand drive Mercedes shortly after the incident.
He was seen running with his left hand inside the right side of his jacket as if he was concealing something.
The gun - a 7.62 Tokarev pistol - was found on the Hallfield Estate in Paddington almost two years after the murder.
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