A spokesperson for Forbes said the company was shocked by the Prince's plans to sue, but was sticking by the story.

"We are very surprised at claims that Prince Alwaleed intends to sue Forbes, particularly if he does so in the U.K., a jurisdiction that has nothing whatsoever to do with our recent story, which raised questions about his claims regarding his wealth," said the Forbes spokesperson.

"The Prince's suit would be precisely the kind of libel tourism that the U.K.'s recently-passed libel reform law is intended to thwart. We would anticipate that the London High Court will agree. Forbes stands by its story."