IT WAS one of the biggest murder investigations ever launched by Hampshire police.

Detectives spent years probing the brutal killing of frail pensioner Georgina Edmonds, who was battered to death in her own home after being tortured for her PIN number.

In 2012 Matthew Hamlen was cleared of killing 77-year-old Mrs Edmonds at her riverside cottage at Brambridge, near Eastleigh, four years earlier.

But the electrician was dramatically re-arrested in 2014 following a relaxation of the double jeopardy law, which had previously prevented anyone being tried for the same crime twice.

Last year Hamlen, 38, was found guilty of murdering Mrs Edmonds and told he would spend at least 30 years behind bars.

Tonight's edition of Crimewatch tells the inside story of how Hampshire detectives involved in Operation Columbian brought her killer to justice.

The programme will show how police secured a conviction four years after Hamlen was originally found not guilty.

Mrs Edmonds was stabbed several times before being battered with a rolling pin.

The programme includes reconstructions and interviews with her son and daughter, Harry and Doddie. Det Insp Martin Chudley, Det Con David Bolton and the senior investigating officer, Jason Hogg, now Assistant Chief Constable of Thames Valley Police, also appear.

Det Insp Chudley unearthed the final piece of evidence needed to convict the killer.

Last year he was recognised at the Police Federation National Detectives’ Forum Awards, where he was named runner-up in the Detective Investigation of the Year category.

The programme comes months after Hamlen’s family offered a £50,000 reward for information leading to his conviction being quashed. They remain convinced of his innocence and have launched a campaign to clear him.

During the second trial jurors were shown CCTV footage of an unidentifiable man, said by the prosecution to be Hamlen, trying to withdraw £200 from a cash machine using the murder victim’s debit card.

Hamlen’s family say the figure dubbed “ATM man” was taller and stockier than the person subsequently jailed for Mrs Edmonds’s murder.

Jurors also heard that following his original acquittal police found new DNA evidence linking him to the crime.

A sample obtained from the victim’s blouse was 26 million times more likely to have come from Hamlen than someone else, the court was told.

But his family, who do not appear in the programme, have cited what they describe as flaws in the system, including cases of DNA being transferred from one person to another via a third party.

Crimewatch is on BBC One at 9pm tonight.