A jury has been shown video footage of a Fenland family allegedly beating a pregnant woman into making a false confession that her partner had murdered their grandmother.

The woman was shown being hit around the head and spat at by members of the family and repeatedly told to admit that her partner had smothered the grandmother as he stole from her house during the night.

Off-camera, voices can be heard telling her: “We could kill you. We are not going to do that: the police are coming. You are going to be safe, but we could kill you.”

Later, the woman is asked: “You’ve got a baby in there – you want us to kill that?”

Prosecutors say the woman and her partner were kidnapped on separate occasions and assaulted, so she made the false confession.

In the video, she says she knew her partner suffocated Gertrude Frankham with a pillow on December 4, 2012 at her Walpole St Andrew home, adding: “He said if I said a word he would kill me.”

She then admitted that the man had continued to rob the house even after the woman’s death.

The jury were shown five clips of the woman’s confession, which took place near Mrs Frankham’s house, ending with the arrival of the police.

Earlier in the trial, the woman told the court via video link that she had been dragged into a car and threatened by a female driver, who hit her, and another female passenger who held something against her neck “which felt like it was metal”.

She was then taken to near Mrs Frankham’s house where she was surrounded by up to 20 people armed with weapons, and was “scared to death”, she claimed.

Mrs Frankham was found to have died of natural causes, despite her family believing she was murdered.

Five people have already admitted their part in what happened to the couple. A further five defendants are charged with kidnap, false imprisonment and wounding with intent.

They are Edward Dolan Jr, 18, of Flower Farm Bungalow, Walpole; 29-year-old Thomas Chilton, 27-year-old Jason Chilton and 57-year-old Violet Chilton, all of Dades Lane, Wisbech; and a 17-year-old who cannot be named for legal reasons. All deny the charges.

Vanessa Frankham, 48, of Wisbech Road, Walpole St Andrew, denies kidnap, blackmail, wounding with intent and robbery, and Diane Evans, 18, of Cherry Road, Wisbech, denies one count of false imprisonment.

The trial continues.