Blake Lively has been accused of attempting to extort Taylor Swift by threatening to release her text messages.

A lawyer acting for Justin Baldoni, a former co-star of Lively’s, made the accusation against the actress in a court filing that has since been struck from the record for its “inflammatory” and “irrelevant” claims.

Lively launched proceedings against Baldoni last year, accusing him of sexual harassment on the set of the romantic drama It Ends With Us, which he directed and starred in, before he counter-sued her alleging defamation, prompting a long-running and bitter legal battle.

The actress asked Swift to delete text messages they had exchanged, according to Bryan Freedman, Baldoni’s lawyer, citing a source “who is highly likely to have reliable information”.

Mike Gottlieb, acting for Lively, is also alleged to have contacted one of the singer’s lawyers and “demanded” she release a statement supporting her, amid the legal battle with Baldoni.

If she refused, Mr Freedman claimed in a letter to the court on Wednesday, “private text messages of a personal nature in Ms Lively’s possession would be released”.

Lively’s lawyers called the claims “demonstrably false” and hit out at the “anonymously sourced, baseless, allegations recklessly levelled without any supporting evidence”.