A Canadian businessman identified as Michael Spavor, is said to be missing in China.
Canadian officials say days after Chinese authorities detained the former Canadian diplomat amid an escalating diplomatic row, they have been unable to contact him.
Spavor had notified the Canadian government that he was being questioned by Chinese authorities.
He is a businessman who is based in the northern Chinese city of Dandong and who runs cultural exchanges with North Korea.
More recently he has been trying to facilitate investment in North Korea in anticipation of sanctions being lifted