The naturalized U.S. citizen, born in South Korea, Kenneth Bae, had traveled several times to North Korea to take tourists and prospective investors to the country, The New York Times reported.
He was taking five European tourists into North Korea through Rajin Nov. 3 when he was arrested, said Do Hee-youn, head of the Seoul-based Citizens' Coalition for the Human Rights of North Korean Refugees.
South Korean daily newspaper, Kookmin Ilbo, cited an unnamed source who said police arrested Bae after finding a computer hard drive that allegedly had sensitive information about the country. Bae was transferred to Pyongyang for further questioning, the newspaper said.
Do told the Times he suspects Bae's interest in helping to feed orphans begging for food could have tipped off authorities.
"The most plausible scenario I can think of is that he took some pictures of the orphans and the North Korean authorities considered that an act of anti-North Korean propaganda," Do said.
Victoria Nuland, spokeswoman for the State Department in Washington, said the department is aware of the arrest.
"We obviously have no higher priority than the welfare of our citizens," she said, declining to comment further on any action to be taken.