Saudi Arabia’s Prince Alwaleed bin Talal, chairman of Kingdom Holding and the Arab world's wealthiest individual, has reportedly launched a libel action against US magazine Forbes.
The legal move comes three months after Alwaleed cut ties with Forbes after accusing it of underestimating his wealth in its billionaires list.
The magazine said the prince was worth $20bn - far less than the $25.9bn estimate by Arabian Business earlier this year and $9.6bn less than his own estimate.
In court documents seen by the UK's Guardian newspaper, Prince Alwaleed Bin Talal claims the magazine used flawed methodology to calculate his wealth and has accused Forbes of purposefully leaving him out of the top 10.
The paper said the prince, whose high-profile stakes include Citigroup, News Corp and Twitter, has filed a defamation claim against the Forbes publisher, its editor Randall Lane and two of its journalists.
Forbes said in a statement: "We're very surprised at claims that Prince Alwaleed has decided to sue Forbes, particularly if he has done so in the United Kingdom, a jurisdiction that has nothing whatsoever to do with our recent story which raised questions about his claims about his wealth.
"The Prince's suit would be precisely the kind of libel tourism that the UK'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."
In April, Prince Alwaleed said that he would pursue Forbes in the courts.
Kingdom Holding's first-quarter net profit rose nine percent year-on-year, but the company's share price has dropped 18 percent since the start of 2013.
Last month, Alwaleed said Kingdom would retain its holding in major investments including Citigroup Inc, News Corp, Twitter and its most recent acquisition, the Chinese online retailer 360buy Jingdong.
Kingdom owns two percent of Citi and seven percent of voting shares in Rupert Murdoch's News Corp. It has invested $300m in Twitter and $160m in 360buy.