MAINZ, Germany — Arnold Schwarzenegger was detained and could face a criminal charge after being stopped by customs officials at Munich Airport, officials in Germany said Wednesday.

The “Terminator” actor and former California governor was stopped for a routine check on arrival on Wednesday and questioned for 2 1/2 hours before being allowed to leave, an airport customs spokesperson told NBC News.

“Criminal proceedings were launched” against him, the spokesperson said, but they would not confirm the nature of those proceedings, citing Germany’s strict privacy laws.

A source close to Schwarzenegger said that the actor, 76, was detained over a luxury watch he had brought into the country while en route to a charity event in Austria, his birth country. The watch was intended to be a prize at a charity auction on Thursday in aid of the Schwarzenegger Climate Initiative, the source said.

“He cooperated at every step even though it was an incompetent shakedown, a total comedy of errors that would make a very funny cop movie,” the source said.

The source said that Schwarzenegger agreed to pre-pay any taxes on the expensive item, but couldn’t find a working credit card machine. Officers then walked him to an ATM at the airport for him to withdraw cash — but the withdrawal limit was too low and the bank was closed, the source said. A second credit card machine worked and the tax was paid.

“The watch will likely still be auctioned tomorrow, and the Schwarzenegger Climate Initiative will properly report it, as all of Arnold’s non-profits do,” the source said Wednesday.

Schwarzenegger was due to host a dinner and charity auction Thursday night in the Austrian ski resort of Kitzbühel, part of a weekend of activities to mark an annual Alpine skiing competition. A news release from his foundation said that among the prizes is a training session with Schwarzenegger.

The proceeds will go towards environmental projects and the annual Austrian World Summit climate conference in Vienna, organized by the Schwarzenegger Climate Initiative.

“‘Whenever people say to me, ‘You are the perfect description of a self-made man,’ I thank them, but tell them they can call me anything they want — but not self-made. I got a lot of help throughout my life and we all need help,” Schwarzenegger said in the news release.

He continued: “So tonight we ask for help. We have to give back and change the world. Today we can all give back by helping to create a cleaner and healthier future.”

Andy Eckardt reported from Mainz, and Patrick Smith from London.