In what will certainly be the most scrutinized ship arrival in Japan in many years, a North Korean cargo-passenger ship is scheduled to dock Monday at a port in Niigata Prefecture. The vessel has made many trips to the port in past years but is now suspected of smuggling.

The 9,600 ton Man Gyong Bong 92 has been one of impoverished North Korea's few major trade connections with the outside world and its only direct transportation link with Japan. The vessel brings to Japan expensive matsutake mushrooms, ginseng and other such items desired by Japanese. In return, it stocks up on mikan oranges, potato chips, mayonnaise and hundreds of other mundane items, most likely intended for consumption by Pyongyang's elite.

But in recent months, police here along with North Korean defectors have claimed that the ship has been also bringing in illegal cash remittances and instructions to North Korean spies in Japan. And it is alleged that the ship has left with components to help North Korea build missiles and, possibly, weapons of mass destruction.

With the ship suddenly in the spotlight for its first visit in five months, Japanese authorities plan to descend on the vessel with one thousand inspectors, the biggest customs check in Japanese history.

Transport Minister Chikage Ogi said every ministry will be tightening its controls of the ship. She said she understands the public has not been satisfied with the level of previous inspections and remains suspicious about the ship's activities. So she says this time the checks will be more thorough.

Such statements have not reassured many local residents.

Outside rail stations in Niigata, opponents hand out leaflets to commuters calling for a ban on the Man Gyong Bong.

A leader of a support group for Japanese abducted by North Korean agents, Mr. Harunori Kojima, says it is inexcusable that Japanese officials allowed the vessel to engage in illegal activities for so many years.

Local politicians, who rarely dare to lambaste the central government, are now doing just that. Niigata Mayor Akira Shinoda said his constituents strongly resent North Korea because of its kidnappings of Japanese and they cannot forgive the Man Gyong Bong being allowed to dock in Niigata.

Government officials in Tokyo say they have no legal reason to bar the ship from entering any Japanese port. But some lawmakers say they may takes steps to allow Japan to ban the suddenly controversial vessel.

While the ship may have no problem getting into port this time, returning to North Korea might not be as easy. The Japanese oil company, which refuels the North Korean ship, says it will discontinue supplying it. The company, which requested anonymity, says it cannot morally bring itself to supply fuel oil to a vessel accused of illegal activities.