Police discovered a “professional” cannabis factory when they raided the West Norfolk home of a couple, and seized 100 plants with a potential street value of £7,800 to £15,000, a court heard.

Police found the plants growing at the St John’s Fen End home of Peter and Violet Chilton in an outbuilding. All the plants had been grown from seedlings, Norwich Crown Court was told.

John Farmer, prosecuting, said the raid took place a year ago, and said it was a “professional set-up.

“This is an operation by which significant commercial quantities are likely to be produced.”

He said that the potential street value was £7,800 to £15,000.

Violet Chilton, 57, admitted being involved in producing cannabis and her husband, Peter, 66, admitted allowing premises to be used.

Tom Buxton for Violet, who is already serving a six year sentence for false imprisonment and grievous bodily harm ,said it was an isolated incident and she had only played a limited function and had been directed by others.

“It’s unlikely this venture would have been set up by her, She had no influence on others who were higher up the chain.”

He said her role was to tend the plants.

David Ewings, for Peter Chilton, said there was no evidence he would have any financial gain from allowing the premises to be used.

Judge Holt said he had to look at the totality of any sentence on Violet and imposed a 26 month jail sentence to be served concurrently with the six year term she is already serving.

He gave Peter Chilton 200 hours unpaid work.

Violet Chilton was jailed in April, this year, after she along with 10 members of her West Norfolk family were jailed for their part in kidnapping and attacking a couple they falsely suspected of being involved in the death of her mother Gertrude Frankham, who died at her home in Walpole St Andrew, aged 75, in December 2012.