ONE of Britain's most baffling hoaxes is to remain unsolved.

Police have confirmed they will no longer pursue Jack - the man behind the infamous Yorkshire Ripper tape - because of the amount of time that has gone by.

The man with a north- eastern accent tormented police at the height of the country's biggest-ever murder hunt by sending them a mocking tape.

And it threw detectives off the scent of Bradford lorry driver Peter Sutcliffe, who killed 13 women and tried to murder seven others.

Detectives believed the taped message - which began with the chilling words "I'm Jack" - came from Castletown in Sunderland. They ordered officers to eliminate from inquiries anyone who did not have a north-east accent.

Sutcliffe, who was jailed for life in 1981 after being caught in South Yorkshire, had a quiet Yorkshire accent.

The bearded lorry driver struck twice in Huddersfield. He killed teenage prostitute Helen Rytka in Great Northern Street, Hillhouse, and tried to murder teenager Theresa Sykes in Oakes.

Now, West Yorkshire Police have said in a statement that the 25-year gap since the tape inquiry began means they can no longer take action.

"The offender cannot be prosecuted for wasting police time, because of the time that has expired.

"We have no plans to continue with the matter".

The tape followed several letters sent to former Grange Moor-based detective George Oldfield, who was leading the Ripper hunt.

He ordered a £1m publicity campaign to try to find the writer of the letters and the man on the tape - but no-one was ever found.

Sutcliffe is now locked up in Broadmoor, having been found criminally insane after being jailed.