A SUPERMARKET chain has denied claims prison labour was used to produce charity Christmas cards after a mum from Braintree received a surprising message inside a pack.

Jessica Rigby, 27, opened a pack and found a message which read "Wishing you luck and happiness. Guangzhou Prison. Number 6 District" in Mandarin.

Miss Rigby said: "I went shopping in Sainsbury’s in Braintree and noticed they had a new Christmas aisle.

“I bought the card, they were a pack of ten Sainsbury’s Christmas snowy penguin charity cards, so I picked them up.

“A couple of days later I was writing out my cards, opened the first card and there was writing inside.

“I didn’t even know it was Chinese, I didn’t recognise the writing so I wanted to know what it said.

"I posted it on Facebook to ask if anyone knew what this said, and again on Twitter to see if anyone got back to me.

“A Chinese friend told me it what it said.

"I just found it odd and funny, and it has made my Christmas a little bit more interesting.”

The charity Christmas cards help support The Royal British Legion and Comic Relief.

She added: "From what I’ve heard it definitely is a prison as I know in Chinese prisons they get the prisoners to work and make things.

“For me, I don’t have a problem as the prisoners are working and charities are benefitting from their work.

“Although it is odd and funny, Sainsbury’s may not know where their cards are coming from and this is important.”

A spokesman for Sainsbury’s said: “All our suppliers have to meet our high welfare standards and strict code of conduct for ethical trade.

“We can also reassure Jessica that our Christmas cards are not produced in Chinese prisons.”

The note was handwritten but its authenticity has not been verified.