Melania Trump has filed a lawsuit in the US state of Maryland

Melania Trump's decision to launch legal action against the Daily Mail is unusual but unsurprising, according to a British lawyer.

Mrs Trump, wife of Republican presidential candidate Donald Trump, has filed a lawsuit, against the Mail and an American blogger, at a court in Maryland, in the United States.

Paperwork indicates that Mrs Trump is seeking more than £50,000 damages from Mail publishers and says the Daily Mail Online published an article referring to her ''very racy past''.

The Mail has published a "retraction" stressing that the article did not intend to state or suggest that "allegations" were true.

London solicitor Sarah Webb said Mrs Trump had been the subject of "enormous media interest" and had an international reputation

"This is a notable and unusual move by the wife of a presidential candidate," said Ms Webb, a specialist in privacy and media issues at law firm Payne Hicks Beach.

"Mrs Trump has been the subject of enormous media interest."

She said the United States had always been a "difficult place to sue for defamation" because legislation afforded wide protection afforded to comments about "public figures".

But Ms Webb said the legal landscape was changing and added: "Given the international nature of her reputation ... it is unsurprising that Melania Trump is now pursuing claims."

The Mail said in its retraction: ''The article discussed whether allegations being made about Melania Trump could negatively affect her husband Donald Trump's presidential bid."

The retraction went on: "The article ... did not intend to state or suggest that these allegations are true ... To the contrary (the article) stated that there was no support for the allegations, and it provided adamant denials from Mrs Trump's spokesperson ... The point of the article was that these allegations could impact the US presidential election even if they are untrue."