Animal rights activists claimed victory yesterday after the owners of a guinea pig breeding farm announced they had closed the business following a six-year hate campaign.
But their local MP said the closure would set back research into cures for cancer and other fatal diseases.
The Hall family is to stop breeding the animals at Darley Oaks Farm, in Newchurch, Staffordshire, after enduring death threats, hate mail, bomb hoaxes, arson attacks and the desecration of a relative's grave.
Police have responded to more than 460 incidents over the past three years.
Friends, employees, neighbours and even the children of brothers Chris and John Hall have suffered threats or violence.
And in October 2004 campaigners took the body of Mrs Hammond, Chris Hall's mother-in-law, from her grave in Yoxall, near the farm.
The Hall family has bred guinea pigs for more than 30 years, sending them to dozens of customers, including research laboratories, but this is to end following a vicious campaign of intimidation.
Last nightfri the Hall family again appealed for the return of Mrs Hammond's body.
In a statement, they said: " David Hall and Partners' involvement in guinea pig breeding for bio medical research has now ceased following the phased closure in recent months.
"We now hope that as a result of this announcement Gladys Hammond's body will be returned to its rightful resting place.
"The certificate of designation which allows the breeding and supply of animals for medical research, and is issued by the Home Office, has now been returned."
In 1999 the Save The Newchurch Guinea Pigs campaign began peaceful weekly demonstrations on the main road outside the farm.
Then activists broke into the sheds and removed about 600 guinea pigs, publishing gruesome accounts of their living conditions on the internet.
While the peaceful protests continued, extremists targeted employees and friends of the Halls and eventually the entire village of Newchurch. Even the local pub, the Red Lion, was forced to bar the family.
The abuse culminated in October 2004 with the ghoulish theft of Mrs Hammond's body.
Protesters yesterdayfri said they were delighted with the farm's closure.
Amanda Richards, spokeswoman for Save The Newchurch Guinea Pigs, said: "We think it is fantastic news. The guinea pigs are packed in cramp and appalling conditions.
"The animals are so stressed that mothers are eating their own young. Those that survive to be sold are tortured to death."
Asked about the campaign of harassment, she said: "We aren't concerned with the reasons why they are closing.
"Our concern has always been the animals."
However, MP Michael Fabricant (Con Lichfield) said seriously ill patients would suffer as a result of the closure.
"Will guinea pigs now have to be imported from Europe where the tough regime of inspections to safeguard the welfare of the animals does not exist?
"Will research on cures for cancer, multiple sclerosis, and other killer diseases be hindered?"
He added: "I will be among the first to rejoice when the day comes that animal experimentation for medical research will no longer be necessary.
"But until that day arrives, it is the duty of our state to protect those who seek to alleviate suffering through illness even if it means that researchers have to experiment on animals.
"I regret that the Hall family and others have not received adequate protection."
Staffordshire Police said it remained committed to recovering the body of Gladys Hammond.
In a statement, a force spokesman said: "The closure of the business will not affect the force's commitment to returning the body of Gladys Hammond - the mother-in-law of Christopher Hall - to her family.
"Staffordshire Police will continue to permit lawful, peaceful protest wherever it takes place while rigorously enforcing the law when it is broken."
* Four people appeared in court last year charged with conspiring to blackmail David Hall and Partners and others connected to Darley Oaks Farm between September 1, 1999, and September 27 2004. They are awaiting trial.
