A $100,000 reward has been offered for information about the murder of a Sydney security guard shot dead during a robbery almost three years ago.
Gary Allibon, 59, was shot in the back during an armed hold up in the centre of Sydney in June 2010.
He and a colleague had been making an early morning cash delivery when they were ambushed by four men in Sussex Street.
Gary Allibon was shot and killed, no one has ever been arrested for the murder.
The men fled the scene in a stolen, silver-coloured, high-performance Audi S8 sedan.
For the third time since her husbands death, Gary Allibon's widow Monica has fronted the media to plead for information.
She wept as she spoke of how much she missed her husband and says she hopes the reward will help to lead to an arrest.
"My husband was killed by someone who can only be described as a cold-blooded murderer," Mrs Allibon said.
"The murder of someone you love changes your life forever.
"It's nearly been three years since we lost Gary and I feel as empty today as I did the day of his death. I'm hoping this reward will convince someone to come forward and provide
detectives with the missing links they need to catch Gary's killer.
"If you have any information at all regarding Gary's death, please contact police."
Police minister Michael Gallacher said the smallest bit of information could help solve the crime.
"Monica Allibion has lived for nearly three years, not knowing who took the life of her husband or why," he said.
"She deserves to know.
"Gary Allibon was just doing his job, minding his own business when he was fatally shot.
"Someone out there knows who did this, now is your opportunity to speak up," he said.
Commander of the Robbery and Serious Crime Squad, Detective Superintendent Luke Moore, says police are keen to hear from anyone with information.
"No matter how irrelevant or seemingly insignificant the information might seem, it could be the much-needed piece of the puzzle we need to find the people responsible for Mr
Allibon's death," Detective Superintendent Moore said.
The NSW Government's reward of up to $100,000 is available for information that leads to the arrest and conviction of those responsible for Mr Allibon's death.