The capture of the Omagh bombers could hinge on vital new forensic evidence, it emerged tonight.
Detectives were believed to be studying DNA samples as part of a widening investigation into the August 1998 attack which killed 29 people.
Even though they have identified and even questioned the men they suspect, the 24-strong investigation team has been unable to gather enough evidence to press charges.
But Assistant Chief Constable Sam Kinkaid today indicated police were now looking at new forensic techniques to come up with a breakthrough.
He said: "There are types of forensic examination that can be carried out now that weren't always available."
Plans to explore new scientific techniques emerged as a new report into the hunt for the "Real IRA" bombers confirmed all barriers to progress have been removed.
Merseyside deputy chief constable Mr Mike Tonge, the man brought in to monitor the investigation, also signalled advanced DNA procedures offered huge hope.
He added: "The search for those responsible for murdering 29 people and two unborn children has been given a new momentum."
Mr Tonge and another senior Merseyside officer, Mr Phil Jones, were called in to quality assure the inquiry following a damning assessment by Police Ombudsman Nuala O'Loan.
Special Branch officers failed to alert officers in Omagh about dissident republican plans to attack the town, she found.
Former chief constable Sir Ronnie Flanagan was also accused of defective leadership in a withering attack just before he stepped down.
In a bid to defuse the row and reassure relatives of those killed in Omagh, the Policing Board brought in Mr Tonge last May to monitor and report on progress in the investigation.
His review found all sections of the police were working together to maximise all intelligence opportunities.
"There's no hiding the fact that we have been able to open doors that perhaps in the past were not quite so open," he said.
"I have not had blockage in any area. Every request we have made has been granted."
Later Mr Jones and Northern Ireland Chief Constable Hugh Orde briefed Omagh victims' relatives on the report. Mr Michael Gallagher, whose son Aidan (21) was killed in the blast, said he was heartened by the meeting.
He said: "Given all the forensic changes that have taken place since 1998 there's every possibility that this investigation will lead to positive results."
Mr Orde had assured the families that the Omagh probe remained the largest investigation being conducted by his detectives.
"We recognise that there's a very good team working on this now," he added. "But having said that nearly five years is a long time for the families to wait."
PA