The search was launched on Tuesday after new information came to light regarding the location of the body but despite spending two days in the water their efforts proved unsuccessful.

The investigation was led by Northamptonshire Police and involved divers from the force in Lincolnshire, who focused their attentions on a stretch of the channel near Saddlebow Bridge, in Saddlebow.

A spokesman for Northamptonshire Police told the Lynn News yesterday that officers have now returned to Northampton to review the case and decide how to proceed further.

She said that a "heavy object" had been found which was of interest, but is not deemed to be significant.

Detective Inspector Rankin McCarrick, who was in charge of the searches, has thanked local people who may have been inconvenienced by the searches and has encouraged anyone who may still have information to call in.

He added: "We have been in touch with Danny's family and kept them fully up to date with how the search went. The thing we want most of all is to be able to find Danny's body and allow his family to bury him. We will consider to look at how best we can do that."

Mr Hathaway (44), a father-of-two from Corby, in Northamptonshire, disappeared from his home on a new age travellers' site in February 2007.

A murder inquiry was later launched as the disappearance was considered to be out of character and the investigation led officers to believe his body may have been dumped in the Great Ouse Relief Channel.

Divers also searched a stretch of water at Saddlebow Sailing Club, near Lynn, in August last year.

Tony Holland (23), of Broadlands, in Desborough, Northamptonshire, was convicted of the murder earlier this year but police have yet to recover the body.

Anyone with information which may help police find Mr Hathaway's body should contact Northamptonshire Police on 08453 700700 or call Crimestoppers anonymously on 0800 555111.