Police have released CCTV images of two people wanted for questioning over the fatal shooting of security guard Gary Allibon in Sydney’s CBD five years ago.

Mr Allibon, 59, was shot in the back and had his gun stolen early in the morning on Monday, June 7, 2010 on Sussex Street.

Three men robbed a cash delivery van before escaping in an Audi driven by a fourth man.

Mr Allibon had given the men the money he was carrying and his hands were in the air when he was shot.

The Audi was found burnt out in a car park in the western suburb of Milperra two days later.

Investigators said they have established connections between the incident and three other shootings in Sydney.

Gary Allibon, 59, was shot dead during a 2010 armed robbery. (Supplied)

The new footage shows the Audi exiting the M5 at Henry Lawson Drive just before 10pm on June 9, 2010 – just two days after Mr Allibon’s death.

Police said they are trying to identify two men seen in a Mercedes C63 travelling behind the Audi.

Detective Acting Superintendent Mick Sheehy said the gun used to shoot Mr Allibon was used in two other shootings at Vaucluse in 2007 and Merrylands in March 2010.

The shooting may be linked to bikie activity, according to The Sydney Morning Herald .

The newspaper reported that police believe a senior member of the Comanchero bikie gang was involved.

Supt Sheehy said that while police had identified a number of persons of interest, assistance from members of the public was still needed.

Police said they are trying to identify the two men seen in a Mercedes C63 on June 9, 2010. (NSW Police) (NSW Police)