Twenty police officers have joined a team of detectives investigating the "horrific" murder of a farming couple in 1993, as new leads are uncovered.
Harry and Megan Tooze were shot dead in 1993
Harry and Megan Tooze were found dead at their remote farm at Llanharry, near Bridgend, on 27 July 1993.
Their future son-in-law Jonathan Jones was jailed for the killings in 1995, but released in 1996 on appeal.
On the 12th anniversary of the deaths, a police re-appeal was made which led to these fresh lines of inquiry.
The bodies of the Toozes were discovered in a cow shed - they had been shot at close range in an execution-style killing.
The bodies of Harry and Megan Tooze were found in their cow shed
But the killer or killers have never been traced despite police taking more than 1,500 statements.
A poster campaign was launched in Llanharry in July 2005, in an attempt to jog people's memories.
As a result, police said new information was gathered and detectives are now trying to track down the drivers of two cars that were seen in the village at the time of the killings.
Detective Inspector Brent Parry said they remained committed to solving "this horrific murder" and were working on encouraging new leads.
"Officers are actively chasing all those leads, but need more help from the public if they are to put closure to the case," he added.
A statement from South Wales Police said officers were particularly keen to speak to the owners of a black 4 x 4 type vehicle and a red saloon car.
"Part of our focus for now is on two vehicles which were seen in the area close to the farm at the time of the incident," Mr Barry added.
"To date, nobody has come forward and it is so important that we are able to speak with those people if only to eliminate them from our inquiries.
"I am asking people in the area to cast their minds back to that fateful Monday, and question whether or not they noticed anything suspicious or unusual between 11.00am and 3.00pm.
Jonathan Jones went onto marry the Tooze's daughter Cheryl
The couple were last seen alive as they returned home from a shopping trip in their Land Rover at around 1100 BST on 26 July 1993.
Police said neighbours heard the sound of gunshots coming from the area of their farm at 1330 BST and a relative who tried to contact them by phone at 1500 BST could get no reply.
Their bodies were found during the early hours of the next day hidden in a cow shed attached to their home.
South Wales Police began a re-investigation of the Tooze case on the 10th anniversary of the murders.
After being released by the appeal court, Jonathan Jones went on to marry the murdered couple's only daughter Cheryl, who had campaigned for his release.
Mrs Jones said the original investigation had been a "complete and utter shambles but they are doing it now and we have to take it from here".
She said once the killer or killers were caught, the family would be able to move on.
"It's not something you can completely erase, that's not possible," she said.
"It's never going to go away but it would help enormously if we have a result on this."