STOCKHOLM (Reuters) - Teen idol Justin Bieber on Thursday seemed to shrug off the latest controversy surrounding his European tour after Swedish police said they had found drugs on his tour bus but could not link them to any single person.

Teen idol Justin Bieber faced withering criticism Sunday after he visited the Anne Frank museum in Amsterdam and wrote that he hoped the Jewish girl who died in a Nazi death camp would have been a fan. The museum said on its Facebook page that Canadian singer Bieber, 19, had visited the Anne Frank House, where she and her family hid from the Nazis, for more than an hour "with his friends and guards." "Truly inspiring to be able to come here. Anne was a great girl. Hopefully she would have been a belieber," Bieber wrote in the guestbook after the visit, the museum said.

A German official has said that Justin Bieber had to leave a monkey in quarantine after arriving in the country last week without the necessary papers for the animal. The 19-year-old singer arrived at Munich airport last Thursday. Customs spokesman Thomas Meister said on Saturday that when he went through customs he didn't have the documentation necessary to bring the capuchin monkey into the country -- so the animal had to stay with authorities. Bieber performed in Munich Thursday night on the latest leg of his European tour.

Canadian teen heartthrob Justin Bieber has four weeks to produce the necessary papers to pick up his pet monkey Mally from the German customs office, authorities said Monday. Mally, which was confiscated at Munich airport Thursday because the 19-year-old pop sensation was unable to present the requisite forms for importing a live animal, is waiting in a holding pen, the customs office said. "There are four weeks left to present the required documents and claim the animal," Munich customs office spokesman Martin Brandlhuber told AFP.