Wife of Republican presidential candidate Donald Trump, Melania Trump has sued The Daily Mail and Tarpley, a US-based blog, claiming that the two outlets made false and defamatory statements about her involvement in an escort service.
The Daily Mail suggested Mrs Trump may have worked as a part-time escort in New York, and met husband Donald Trump, who is now running for the White House, earlier than previously reported.
Blogger Webster Tarpley wrote that Mrs Trump feared her past becoming public.
The claims were "outright lying", lawyer Charles Harder said.
"These defendants made several statements about Melania Trump that are 100 per cent false and tremendously damaging to her personal and professional reputation," attorney for the real estate mogul's wife, Charles Harder said in a statement.
The suit was filed on Thursday in state court in Montgomery county, Maryland, CNN reported.
"Defendants broadcast their lies to millions of people throughout the US and the world-without any justification," Harder said.
"Their many lies include, among others, that Melania Trump supposedly was an 'escort' in the 1990s before she met her husband. Defendants' actions are so egregious, malicious and harmful to Melania that her damages are estimated at $150 million," CNN quoted the attorney as saying.
Last week, Melania Trump placed The Daily Mail, Tarpley and other news organisations on notice for what she and her attorney said were false and defamatory statements in reports about both her employment and immigration history.
Those notices were sent three days after The Daily Mail, a UK publication, published a report citing a story in a Slovenian magazine that claimed a New York modelling agency that once represented Melania Trump "also operated as an escort agency for wealthy clients", CNN reported
That report was then picked up or referenced by other news outlets, including Tarpley.
Less than two hours after issuing the statement on Thursday, The Daily Mail retracted its story.
"The article... did not intend to state or suggest that these allegations are true, nor did it intend to state or suggest that Melania Trump ever worked as an 'escort' or in the 'sex business,'" The Daily Mail wrote in its statement.