DETECTIVES investigating the triple murder of a family in a Helensburgh house fire have released CCTV images of two people who could be vital to the inquiry.

Officers want to track down the potential witnesses, as well as a car which was captured on camera in the area around the time of the fire.

Eight-year-old Bridget Sharkey and her brother Thomas, 21, were killed in the blaze, started deliberately at their Scott Court flat on Sunday, July 24.

Their father Thomas, 55, was taken to hospital but died six days later.

The children’s mother Angela Sharkey, who was also injured and treated in hospital for weeks after the fire, has been left devastated by the loss of her family.

Strathclyde Police said the individuals in the CCTV footage are potential key witnesses who could possess information that is “critical to the investigation”.

The first person they want to trace was seen walking north in John Street at around 5am on the day of the fire. The individual was wearing a grey or blue top with dark trousers or jeans.

The second person is a white man in his twenties, who is of slim to medium build. He has short brown hair and was wearing a white T-shirt, blue jeans and brown shoes.

The potential witness was seen walking in West Clyde Street a few minutes before the fire was discovered.

Officers are also keen to track down the occupants of a light-blue Renault Clio which was seen in both John Street and West Clyde Street a short time after the blaze was reported.

Detective Superintendent Peter McPike, the officer in charge of the inquiry said: “I believe that both the people who are seen walking in the area and the occupants of the Renault Clio are key witnesses and could have information that is vital to this investigation.

“I would urge them, or anyone who recognises them, to come forward to the police as a matter of urgency and assist us in this ongoing triple murder investigation.”

Despite numerous police appeals for information, the offer of a £10,000 reward and an emotional plea by Mrs Sharkey, officers are no closer to solving the crime.

Detectives previously revealed that they feared “misplaced loyalty” was preventing potential witnesses from coming forward.

There has been speculation the blaze was linked to a feud between families.

Mr Sharkey Snr had been the subject of a recent attack that left him with numerous stab wounds and had been convicted of drugs offences in 1995.

However, police urged potential witnesses to “look at their conscience” and pass on any information that could assist in getting justice for the woman who lost her husband and two children in the devastating fire.

Thomas Jnr was home on holiday from Georgia Southern University at the time of the fire.

He was a student on a golf scholarship and had been due to compete in the Scottish Amateur championship at Western Gailes, Ayrshire, while back in Scotland.

Bridget – who was described as a “brilliant” young girl – was supposed to be at a sleepover at a friend’s house but had called her mother asking to come home.

Mrs Sharkey last month made an emotional appeal for information and said: “The three things I loved most about my life are dead.”

The mother urged anyone with information to “do the decent thing”.