Mr McMorran, who died in 1999, is alleged to have provided the crucial information that allowed the 15-strong team led by Bruce Reynolds to steal £2.6m (around £60m today) from the Travelling Post Office.
An investigation by The Sun previously named him only as “the Ulsterman”.
In August 1963, Mr McMorran was working in the security unit of the General Post Office (GPO) and had access to information on the operations of the mail trains and the sums of cash carried on board.
He joined the GPO in Belfast in the 1940s before moving to work for the organisation in England.
According to the newspaper, Mr McMorran, a Freemason, returned to live in Northern Ireland after his retirement in 1979.
His name was given to Daily Express chief crime correspondent Percy Hoskins by a senior Scotland Yard officer in 1964.
An address in south-east London found among the journalist’s papers by a historian was matched to that of Mr McMorran at the time of the robbery by The Sun.
He was never arrested or questioned by detectives investigating the robbery and had no known links to any criminality.
Mr McMorran’s daughter, Valerie Hoy (78), told the newspaper she doesn’t believe her father was the source who passed information on the train to the gang.
“My dad was very moral, very honest and he was kind of religious. I never remember him being dishonest in anything,” she said.
“It wasn’t him. It must have been another Ulsterman.”
Ms Hoy said it was widely known among staff that sacks on the Travelling Post Office contained money.
“I asked my father, ‘Why did they send so much money on a train from Glasgow to London?’
“He had just taken the security job and told me they had been doing that for year upon year and there had never been any bother and they never had any security.”
Ms Hoy said her father did not have any criminal associates and said he believed the robbery had been “planned even before he got the job”.
The gang had been told the overnight Glasgow to London mail train of August 8, 1963, would be carrying significant sums of cash in its high-value parcels van.
The train was stopped by the rigging of a signal light. The driver, Jack Mills was then coshed, and the staff on board held while the bags of money were taken off.
Most of the gang was eventually caught and jailed, with the ringleaders getting up to 30 years in prison, but the vast majority of the cash was never recovered.
The last robber to be released from prison was Ronnie Biggs, who escaped from Wandsworth 15 months into his sentence in 1965.
He voluntarily returned to the UK from Brazil in 2001 and was ordered to serve the remainder of his term before being released on compassionate grounds in 2009.
Source link