Eric Ford, detained at his home by Federal Bureau of Investigation agents, faces up to 15 years in prison if he is convicted of illegally intercepting the mobile phone conversation last February, taping it and then selling it to The Globe newspaper in the United States.
Mr Ford is reported to have first tried to sell the tape to the News of the World, before The Globe ran a piece last June asking "Is Tom Cruise's Marriage Hanging by a Thread?" and detailing "a lovers' spat between the famous couple".
Mr Cruise and Ms Kidman are bringing a civil suit against the tabloid, claiming that their words were spliced together from different conversations.
A Globe spokesman said his paper did nothing "illegal or inappropriate" in running its story, and no criminal charge has been filed against the paper.
In October, Mr Cruise and Ms Kidman were awarded pounds 200,000 in libel damages from the Express on Sunday.Reuse content