From WENN.com

In legal documents filed in Los Angeles and obtained by TMZ.com, Robert Randolph - the man behind You'll Never Spa in This Town Again - claims Travolta and his attorney Marty Singer falsely alleged the writer had mental issues and had spent time in a mental institution.

In the legal papers, the writer's attorneys state, ""Several of the statements made by Defendant Singer, on behalf of Defendant Travolta, are untrue and amount to defamatory statements sought to disparage the quality of (Randolph's) property and reputation and to induce members of the public to believe (Randolph) is an unreliable source and thus abstain from purchasing"" his book.

The suit, filed by attorneys from Los Angeles firm Golden & Timbol, alleges causes of action for trade libel, intentional and negligent interference with prospective advantage.

According to the website, the plan to discredit Randolph worked - because retailers were deterred from selling his controversial book.

Randolph is suing both Travolta and Singer for unspecified damages.

Travolta was caught up in a spa sex scandal last month (May12) when two masseurs filed and then withdrew and dismissed sexual assault suits against the movie star.