TOKYO (AFP) - Hong Kong-based pop singers Kelvin Kwan and Jill Vidal have been arrested in Japan for marijuana possession, a crime that carries up to five years in jail, Tokyo police said Wednesday. Police arrested 25-year-old Canadian national Kwan and 26-year-old Briton Vidal for possessing 0.2 grams (0.007 ounces) of cannabis while they were out in Tokyo's Shibuya district on Tuesday last week, police told AFP. "Police searched them and found the marijuana among Kwan's belongings, and they said it belonged to both of them," said a Tokyo police spokesman. The storekeeper called police after suspecting they were shoplifting and officers then found the marijuana, the spokesman said, although he was unable to confirm whether they had actually committed theft. Japanese media reported that the marijuana was found rolled in a cigarette. While the two singers have admitted to possessing the drug, they have denied taking it, media reported, quoting police officials. "I just brought the cigarette with me that I was given in Hong Kong," Kwan reportedly told police, according to the Sankei Shimbun. Kwan and Vidal, who are reportedly a couple, participated in anti-drug campaigns in 2007 in Hong Kong. Japan strictly prohibits both hard and soft drugs, and police have in recent months arrested sumo wrestlers, popular musicians and actors, as well as college students, for posessing, growing or selling marijuana. Japan saw a record number of marijuana offences last year, arresting 2,778 people in 2008, 22.3 percent more than the previous year, according to the National Police Agency.