The 'Notting Hill' actor was jetting from London to Los Angeles when he began puffing on the white stick - smoking on planes is banned - causing furious passengers to complain to staff on the Virgin Atlantic flight.
The 41-year-old star caused further concern when he twisted the cigarette around and pressed the burning red ember into his lip - until staff realised it was a fake cigarette.
Rhys was using a SmokeStik, a new invention which allows smokers to get their nicotine hit without having to puff on a cigarette.
The version Rhys was using, the SmokeStik Royale, was designed by socialite Lady Victoria Hervey and features her family's crest.
SmokeStik spokesman Brian Culwell said: "The fact that SmokeStik doesnt fall foul of the smoking ban makes it ideal for people who find it tough to sit through a lengthy transatlantic flight without cigarettes.
The only down side is occasionally you may get challenged by people who mistake them for the real thing!"
Other fans of the product include Leonardo DiCaprio, Paris Hilton and Simon Cowell.
