Gladys Hammond's remains were found after 18 months

The grave of a grandmother dug up by activists in the name of animal rights.

That night in October 2004 was the height of a six-year campaign of hatred levelled at the Hall family, who bred guinea pigs for animal research at Darley Oaks Farm in Staffordshire.

"The desecration of Gladys Hammond's grave went way beyond any rational understanding of protest," said Det Ch Insp Nick Baker.

It was nearly six months after the crime that he made a national television appeal on BBC's Crimewatch programme for the activists to prove they had her body.

Immediately after the programme John Smith collected his accomplices Jon Ablewhite and Kerry Whitburn from their homes in the West Midlands.

THE GUILTY BLACKMAILERS Jon Ablewhite, 36, of Levenshulme, Manchester John Smith, 39, of Leicester Street, Wolverhampton Kerry Whitburn, 36, of Edgbaston, Birmingham Josephine Mayo, 38, of Edgbaston, Birmingham

They drove to Brackenhurst Wood in Newchurch, near the guinea pig farm.

A text sent that night on a phone found in Smith's house read "Flies hoverin, cld be a while - get bread n humus ur goodness!".

At 0600 GMT on 16 March 2005 Smith's car was stopped by police and a collapsible spade, headlamp, balaclava and camouflaged clothing was found.

The three were arrested and released on bail.

Three weeks later "special knowledge" letters using a codeword were sent to BBC Midlands Today, the Burton Mail and to associates of the Halls.

The letters offered to release co-ordinates pinpointing one-sixth of Mrs Hammond's remains in Brackenhurst Wood.

A spade and other equipment was found in Smith's car

But co-ordinates were never provided and in May last year 100 police officers searched the woods for two days. Nothing was found.

In September 2005, the three men along with Josephine Mayo were arrested and charged with conspiracy to blackmail.

"Ablewhite, Smith and Whitburn's decision to drive to Brakenhurst Wood immediately after our Crimewatch appeal last year was a significant breakthrough," said Mr Baker.

"They refused to go to ground following the desecration and continued to target the Halls and their associates, inciting others to do the same."

Body found

At its height 50 detectives were attached to the Yoxall grave desecration case as they investigated the "crime in action".

Police pieced together the case against the three men who stole the body, and Mayo, who was linked to a lit petrol can left outside the home of Sally-Ann Hall, the daughter of the farm's co-owner John Hall.

From October 2004, detectives took 2,114 statements, interviewed 698 witnesses, gathered 3,413 exhibits and prepared about 100,000 A4 pages of evidence at a cost of �750,000.

A typewriter and anatomy books were found in Whitburn's home

Exhibits included hundreds of malicious letters sent to the Halls and many people associated with them.

Evidence found at the homes of the defendants included letter-writing equipment, evidence of research of targets' addresses, and an A to Z map that fell open at the page of Miss Hall's address.

In August 2005, the Hall's announced they were closing down their guinea pig farm and ceased operating in January this year.

Mrs Hammond's body was found on Cannock Chase last week after Smith told police where it was.

The recovery of her remains bringing an end to the four-month wait "endured" by the Halls and the rest of the Hammond family, Mr Baker said.

"Hopefully, they can now, for the first time, experience a sense of closure in the knowledge that Gladys will again rest in peace."