Two people were arrested after campaigners removed a trolly full of fruit and veg from the Tesco store in the centre of Swansea, up-ended it in the entrance and covered the goods with fake blood.
The campaigners, Greg Wilkinson and Dee Murphy, took the dramatic action in protest at the retail giant selling food produced in the West Bank area, land occupied and settled by Israel.
One of "the Tesco Two" has now been charged with theft and will have to appear in court.
Grandmother-of-four Ms Murphy said: "I think the shoppers were supportive of what we did — one elderly couple came over and said it was great.
"We never had any intention of keeping the goods or making a monetary gain from our action. It was done to draw attention to the issue."
The pair were arrested at 3.30pm on Tuesday and taken to Swansea Central Police Station, where they spent eight hours in the cells.
Ms Murphy, from Mount Pleasant, Swansea, was charged with theft, while no charge was laid against Mr Wilkinson.
"I will take legal advice about what to do when it comes to court," said Ms Murphy.
Seventy-two year old Mr Wilkinson, from Brynmill, said he had kept up his spirits while in the cells by singing. "There's lovely acoustics in the cells," he said.
"I must have sung just about every song I know.
"When you are in the cell without a watch or clock, and when you can't see the sun, you loose track of time."
He added: "I have to say the police officers and guards treated us with civility throughout."
The pair said they took the direct action in protest at Tesco selling what they termed "illegally produced food".
"We shouldn't have to do this," said former journalist and Llanelli smallholder Mr Wilkinson.
"The Government is party to international agreements, yet it allows companies to sell goods produced on what is clearly recognised as stolen and occupied land.
"If the Government won't enforce international law, then it is up to good citizens to do it."
Mr Wilkinson has previously protested about Tesco selling goods produced on the West Bank by stealing packets of dates — and writing to the company's chief executive to explain why.
The protesting pensioner has now been banned from Tesco.
A spokeswoman for the supermarket said all its products from the Occupied Territories were labeled according to UK and European guidelines which allowed customers to make an "informed choice" about what they buy.
She added: "While we will always support people's right to their opinion, we cannot accept our customers or staff being harmed in any way."