Denise Richards has responded to her ex-husband Charlie Sheen's claims that she cashed a cheque he wrote to her as part of a prank.

The Wild Things actress and reality star has denied her ex-husband's claims that she cashed a cheque for $1 million (£750,000) that he had written to her "as a joke" on her birthday.

On Thursday, Richards took to Instagram to share a photo of the cheque, which she said she had recently found while moving house.

"Found this during my recent move. I never cashed it, @charliesheen," she wrote over the image, before adding playfully, "Is it still good?"

Sheen had spoken about the unusual prank earlier in the week, during an appearance on Kevin Clancy's KFC Radio podcast.

"I wrote a cheque to Denise once for $1 million on her birthday, kind of as a joke, and she kept it not as a joke," the Two and a Half Men star said. "And then, like, a month later, f**king cashed it."

The actor went on to admit that he couldn't recall whether they were still married at the time.

"Yeah, which makes it sting more?" he said. "But you know, if I'm on the other side of that, I'm probably cashing that cheque."

Sheen has yet to comment on Richards's post.

The cheque appears to be dated 24 December 2011, five years after the couple's divorce was finalised.

Richards and Sheen married in June 2002 and split in 2006. They share two daughters, Sami, 21, and Lola, 20.