The TV presenter was followed around the Central London store by a plain-clothes security guard, who watched her allegedly put around £70 worth of mascara, foundation and eyeliner into her pockets and shopping bags.
She was taken to a back room and asked to return the items, but staff decided not to involve the police, according to the Sunday Mirror.
A witness said: "I noticed her browsing in the make-up aisle, just the normal cosmetics like Rimmel and L'Oreal. I was really surprised to see her openly picking stuff up - foundation, mascara, eyeliner - and putting them in her coat pockets and in her Selfridges bag.
"She looked around a bit but didn't seem bothered, just dropped them in like it was a normal thing to do. When she left she went right to the back of the store so she didn't go past the tills. A store detective followed her outside and brought her back in. I heard him say, 'Do you know why I've brought you back?'
"I didn't hear her response but she was completely cool. You'd think someone would be embarrassed or upset, but she was totally casual as though it was nothing out of the ordinary. He took her into a back office and five minutes later she came out and left the store, calm as you like again."
A staff member later confirmed to the paper that Geldof had been banned from the store and wasn't arrested because she gave the products back.
Geldof refused to comment while Boots said it cannot comment on individual customer circumstances."
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