The party-loving Lotus driver, second in the championship at present, is a big fan of Britain's 1976 champion and once entered a snowmobile race under Hunt's name. He has also paid tribute to him in the past with Monaco helmets.
This year's had the words 'James Hunt' on the top, positioned to face the camera behind. The regulations do not allow rear-facing messages.
A Lotus team spokesman said the 2007 world champion would cover the words.
Formula One's commercial supremo Bernie Ecclestone appeared unaware of the controversy when asked by a reporter and a representative of Formula One Management suggested any intervention might have come from the company's ever-watchful lawyers.
Hunt's title win, in a battle with Austrian Niki Lauda, is the subject of a new biopic 'Rush' due out later this year and that may also have played a part in the decision to order the cover-up lest the helmet be seen as a movie promotion.
Raikkonen is not the only driver paying his respects to former racers.
Toro Rosso's Frenchman Jean Eric Vergne has 'Cevert' on the side of his helmet in a tribute to compatriot Francois Cevert, killed in practice for the 1973 U.S. Grand Prix.
Red Bull's triple world champion Sebastian Vettel has a photograph of Stirling Moss in action in Monaco on top of his helmet.
The rear has a drawing of a kneeling woman in a swimsuit, whose clothing disappears when the image reaches a certain temperature.