Wendy Sewell: Victim of a brutal attack

The committee will include a representative from the Crown Prosecution Service, a senior barrister, and a recently retired senior officer from another force.

"The reinvestigation will be thorough and open to independent scrutiny throughout," said Mr Coleman.

"I am confident that it will help to allay any public concerns."

The investigation, led by Detective Superintendent David Gee, should end by the autumn.

Signed confession

Wendy Sewell, a 32-year-old typist, died after being savagely beaten with a pickaxe handle in Bakewell cemetery.

Mr Downing, who was then a 17-year-old groundsman, signed a confession which he later retracted.

He was convicted and told he would have to serve a minimum of 17 years.

But as he always maintained his innocence, he ruled himself out of consideration for parole.

He was freed with the help of a campaign by the local newspaper, the Matlock Mercury.

We are delighted of course and we'll be prepared to give any help we possibly can

Ray Downing

Judges decided that since the initial confessions might not be reliable, Mr Downing's conviction was unsafe.

However, they stopped short of declaring him innocent.

Their decision prompted calls for the murder inquiry to be reopened.

Stephen Downing's father Ray told the BBC on Tuesday: "I suppose in a way it's a bit of a surprise.

"Not that it's reopened, but that it's come through so quickly - we knew the police were looking into the possibility of reopening but it's not really sunk in yet that the time has come that they are going to do something.

"We are delighted of course and we'll be prepared to give any help we possibly can."