A key piece of evidence which supporters of a convicted killer claim could prove his innocence is at the centre of a legal dispute.

Michael Stone, from Gillingham, is serving life for the murders of Lin and Megan Russell nearly 20 years ago but still maintains his innocence.

A row has broken out between his legal team and Kent Police over a shoelace found near the murder scene which has allegedly been lost.

Mark McDonald, his barrister, says when the Criminal Cases Review Commission investigated, it asked for the lace to be made available so it could be retested using modern DNA technology.

He says the evidence bag containing the lace was empty.

“The Forensic Service say the shoelace was in the bag when they sent it back to the police stores, so where is it?” he said.

Kent Police say the lace is not lost, but as parts of it have been tested so many times, any DNA evidence on it has now been exhausted.

Mr McDonald told KentOnline's sister paper, the Medway Messenger: “Well if they have got the lace, I’d like to see it.”

Stone’s sister Barbara, who spoke out last week about her fight for justice, said: “As we understand it the bootlace tourniquet used as evidence in the trial has now been lost by Kent Police while in their property.

"It had DNA on it – it was not my brother’s – so presumably it is the killer’s.”

In a statement a spokesman for Kent Police said: “The shoelace seized as part of the original investigation has not been ‘lost’.

“However, after repeated and exhaustive testing, where sections are removed, the disintegration has been such that only fibrous strands of the lace are left.

“All evidence from those examinations has been recorded and disclosed.

“Full disclosure of all evidence and exhibits was given throughout the legal processes.”