Media playback is unsupported on your device Media caption Devon and Cornwall Police began excavation work at the property in Bradninch, Devon, on Wednesday morning

The garden at the former home of a paedophile couple, who knew serial killers Fred and Rose West, is being excavated by police.

Police are searching for the body of a baby at the property in Bradninch, Devon, the BBC understands.

David Williams was jailed for life in 2015 and his wife Pauline for 12 years for putting 10 girls and boys through rape, sexual assault and beatings.

The couple became friends of the Wests in Gloucester in the 1980s.

Image copyright Devon and Cornwall Police Image caption David and Pauline Williams were jailed for abusing boys and girls

A force spokesman would not confirm exactly what officers were looking for, but sources close to the investigation told BBC South West Home Affairs correspondent Simon Hall they were searching for a baby.

The couple are believed to have lived in the house for only a few years before they were sentenced last year.

A neighbour, who preferred not to be identified, said: "I think it's awful what could be under the tarpaulin there.

"Hopefully they will find nothing. It would be unthinkable if they did."

Image caption The couple are believed to have lived in the house for only a few years before they were sentenced last year

She said the couple had kept "themselves to themselves" for the short time time they had lived there.

"They didn't smile and wouldn't make eye contact," she said.

She said residents were in "shock".

"We are a sleepy town and to have this investigation is terrible," she said.

"Our town wants to be on the map for being a beautiful place in Devon, not for these terrible crimes."

Image caption The couple became friends of the Wests in Gloucester and later moved to the property in Bradninch, Devon

TIMELINE

1980s/90s: David and Pauline Williams live near child murderers Fred and Rosemary West's home in Cromwell Street, Gloucester

1989: The Williams start abuse of children as young as seven

1991: The couple run the Prince Albert pub in Gloucester where Fred West was a regular

1994: Rosemary and Fred West arrested, accused of murdering 12 people over a period of over 20 years

1995: Fred West kills himself in jail

1995: Rosemary West sentenced to life

1990s: David and Pauline Williams move to Devon to run the Victoria Inn in Exeter. Abuse continues until 2004

2013: Operation Abbey investigation into the Williams starts

2015: David and Pauline Williams jailed for a total of 35 years for sexually abusing 10 children over a 15-year period

2016: Police begin excavations at the Williams' home in Bradninch, near Exeter

Image caption Police are carrying out an intensive search at the property

Image caption Tarpaulin and scaffolding surrounds the property

Last year a court heard that David Williams had boasted of his connections with the Wests, who drank at the Prince Albert pub he ran in Gloucester.

The Williamses, who are both in their 50s, started abusing children in the late 1980s when they were running the pub. One victim was seven years old.

They also ran the Victoria Inn in Exeter after moving to the city in the 1990s, where they went on to abuse a string of teenagers.

At their trial, they denied a total of 46 charges of sexual and physical abuse between 1989 and 2004.

David Williams was found guilty of 10 rapes, 13 indecent assaults, five counts of gross indecency, two of cruelty and one of sexual activity with a child.

Image copyright PA Image caption Rose West was convicted of 10 murders in November 1995 and is serving life while Fred West hanged himself in prison in January 1995

His wife was found guilty of two rapes and five indecent assaults.

They were found not guilty of eight other allegations involving two other complainants.

The investigation into the pair, named Operation Abbey, began in July 2013 when a woman disclosed to a mental health professional that she had been raped and sexually abused by David Williams when she was 15.

A police spokesman said: "Devon and Cornwall Police are undertaking excavation work at a property in Bradninch near Cullompton.

"This relates to historic intelligence connected to the address and its former occupants. It is expected to take up to four days to complete.

"Specialist officers will be involved in the excavation, which we hope will have as little impact on the local community as possible."

Fred West was awaiting trial on 12 murder charges when he hanged himself in prison in January 1995. Rose West was convicted of 10 murders in November 1995 and is serving life.

The charges related to the deaths of young women over a 20-year period.