A giant advertisement of the 'The Da Vinci code ' movie hangs on the facade of the Rome's San Pantaleo church, 24 April 2006. - 

A squabble between Opus Dei, the exclusive Catholic organization, and a small Danish game-maker, has ended up in court. At issue is a card game.

"Opus Dei: Existence after Religion" is a strategy-based game built around the world of philosophy.

But the religious organization claims the company Dema Games, has no right to use its name. Game inventor Mark Rees Andersen obtained copyright for the full name in 2009. He says Opus Dei, which means "work of God" in Latin, is a concept that has existed for centuries.

"It's preposterous to think that one organization can have the sole rights to this concept," he says, "because if you have the right to define the work of God then you also have the right to define God via his work and that is insanity."

The organization is accusing Andersen of "riding on the coat tails" of the Da Vinci Code -- Dan Brown's award winning book which portrays the religious order as a sinister and sadistic sect.

Opus Dei is demanding more than $50,000 in damages and wants the website where the card game is sold to be shut down.

A verdict is expected in March.