Foreign ministry spokesman Lu Kang told reporters at a press briefing Michael Spavor, head of Paektu Cultural Exchange, was detained at the Chinese border city of Dandong, South Korean newspaper Kyunghyang Shinmun reported.
Spavor said in one of his most recent Facebook posts he was planning a trip to Seoul, but did not arrive by Monday as planned, BBC News reported.
Lu said Thursday Spavor is under investigation by China's state security bureau in Dandong. He was arrested on charges of "harming [Chinese] national security," but details on the reasons for his detention were not provided by Beijing.
Spavor, who organizes business, culture and tourism trips to North Korea, is best known for organizing NBA Hall-of-Famer Dennis Rodman's visit to Pyongyang.
The timing of Spavor's arrest has given rise to speculation that China could be retaliating in response to the arrest of Meng Wanzhou, chief financial officer of Huawei. Meng was arrested Dec. 1 in Vancouver, at the request of the United States.
Meng could face extradition for fraud and denies violating U.S. sanctions on Iran through Huawei's transactions.
Following her arrest, China has threatened "unspecified consequences," BBC News reported.
Spavor's arrest was publicly disclosed only a few days after a former Canadian diplomat, Michael Kovrig, was arrested in Beijing "on suspicion of engaging in activities that harm China's state security."