French first lady Valerie Trierweiler has been hospitalised in Paris following revelations about an affair between French President Francois Hollande and an actress, French daily Le Parisien said on its website.

On Friday, Hollande threatened to sue celebrity magazine Closer, complaining of breach of privacy after it alleged he was having an affair with actress Julie Gayet.

The Elysee presidential palace spokesman could not immediately comment on the report. Trierweiler's spokesperson was not immediately available.

Le Parisien said that Trierweiler, shaken by the revelations about the affair, had been taken to hospital on Thursday, right after hearing about the liaison.

The paper said doctors had prescribed rest and that she would be release in a few days.

Hollande and Trierweiler, a journalist for celebrity magazine Paris Match, are not married but have been in a long-term relationship for several years.

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