A Tooting family who found a message from a Chinese prisoner in a Christmas card said they thought it was a "prank" when they first read it.

Florence Widdicombe, age six, was writing cards to school friends last weekend when she found the note saying: "We are foreign prisoners in Shanghai Qingpu prison in China.

"Forced to work against our will. Please help us and notify human rights organisation."

The author asked the recipient to get in touch with journalist Peter Humphrey, who spent two years incarcerated in the same jail between 2013 and 2015.

Florence told reporters: "We didn't open [the cards] on the day that we got them, we opened them about a week ago.

"We were writing in them.

"About on my sixth or eighth card, somebody had already written in it."

Her father, Ben Widdicombe, said he felt "incredulity" and thought it was a "prank" when he read the message.

He explained: "On reflection, we realised it was actually potentially quite a serious thing, so I felt very shocked, but also a responsibility to pass it on to Peter Humphrey as the author asked me to do."

Mr Widdicombe passed the details of the "strange occurrence" to the journalist via LinkedIn, and said the message arriving just days before Christmas made it "very powerful".

Mr Widdecombe said: "It hits home, there are injustices in the world and difficult situations that we know about and read about each and every day.

"But there's something about that message hitting home at Christmas, and so close to Christmas, that really does make it very poignant."

The family then reiterated the significance of the chance discovery to their daughter.

Wandsworth Times:

Mr Widdicombe said: "We explained that the person who wrote it was a prisoner in China and that the person felt the prison guards were being mean, making them do work, they felt really sad.

"They wanted to tell people about that, so they had written this note that we found."

Mr Humphrey was arrested while working in Shanghai as a corporate fraud investigator after his work angered the Chinese authorities.

Both he and his wife were jailed without trial and handed hefty fines - they were eventually released early on medical grounds.

Writing in the Times, Mr Humphrey said he had kept in touch with some inmates for a while after his release but said censorship of outbound and inbound letters had been tightened significantly in the last year.

The card with the message on it had been made at Zheijiang Yunguang Printing, and a Tesco spokeswoman told the PA news agency that the company was "shocked" and had shut down operations at the facility.

"We would never allow prison labour in our supply chain," she said.

Tesco donates £300,000 each year from the sale of its cards to the British Heart Foundation, Cancer Research UK and Diabetes UK.

The message in the card is not the first of its kind - in 2017 Jessica Rigby from Braintree, Essex, found a handwritten note in a box of Sainsbury's Christmas Cards.

Translated, the note read: "Wishing you luck and happiness. Third Product Shop, Guangzhou Prison, No 6 District."

In 2014, Karen Wisinska from Co Fermanagh, Northern Ireland, found a note on a pair of Primark trousers reading: "Our job inside the prison is to produce fashion clothes for export.

"We work 15 hours per day and the food we eat wouldn't even be given to dogs or pigs."

The author claimed to be incarcerated in the Xiang Nan prison in Hubei province.