Arnold Schwarzenegger was stopped for hours by customs at Munich Airport after entering Germany with a luxury watch that was potentially to be auctioned at a charity event.

The former film star and California governor was stopped for a routine check after arriving on Wednesday, customs spokesperson Thomas Meister said.

Schwarzenegger was able to leave after about two-and-a-half hours, he said on Thursday.

Goods over the value of 430 euros (£368) that will stay in the European Union have to be declared and, where appropriate, duty paid on them.

German daily Bild, which first reported on the incident, reported that the allegedly undeclared watch made by Swiss manufacturer Audemars Piguet was valued at about 20,000 euros (£17,129) by Schwarzenegger, for whom it was specially produced.

The Schwarzenegger Climate Initiative said that Schwarzenegger was detained “for travelling with a watch he owns, that he might be auctioning at his charity auction (on Thursday) in Kitzbuehel”, in neighbouring Austria.

It added in an emailed statement that Schwarzenegger “co-operated at every step even though it was an incompetent shakedown” and that he agreed to “prepay potential taxes on the watch (remember, it is his personal watch)”.

It said that the watch was still likely to be auctioned and the climate initiative “will properly report it, as all of Arnold’s nonprofits do”.

Schwarzenegger’s charity auctions raise millions of dollars every year for after-school programmes for children across the US and environmental work around the world, it added.

The matter now goes to a customs penalty body in Augsburg, which will evaluate the case.