No senior North Korean officials are aboard the North Korean ferry Man Gyong Bong-92, which is due to arrive Monday in Niigata amid a political uproar over its alleged involvement in illegal trade and espionage activities, sources said.

Japanese public security authorities say North Korea has used the 9,672-ton passenger-cargo ferry as the contact point for senior party and intelligence officials to meet with their operatives in Japan.

The sources said they used the manifest of the 76 crew members that agents for the Man Gyong Bong in Japan filed with Japanese authorities and other information to determine that no senior North Korean officials are on the ship this trip.

Japanese authorities allege that the Man Gyong Bong, which plies between Wonsan in eastern North Korea and Niigata port on an irregular basis, has been involved in smuggling contraband materials for potential military use, unauthorized money remittances and clandestine activities.