North Koreans aboard a recently impounded vessel off northern Japan on Wednesday refused to respond to police questioning over allegations they stole home appliances from an uninhabited islet, despite earlier admitting to the crime, investigative sources said.

The wooden boat bearing a name plate indicating the vessel belongs to the North Korean military was found off the islet off Hokkaido on Nov. 28, with 10 men aboard.

The hut, located near a shelter port, had been locked but was broken into and ransacked and the home appliances, such as a TV and refrigerator, had been taken.

The North Korean crew had earlier admitted to stealing home appliances from the hut, saying "because nobody else was around," investigative sources said.

However, when the police tried to question a man who appeared to be the boat's captain on Wednesday morning to further look into the case on a voluntary basis, he declined to cooperate, the sources said.

The Japan Coast Guard have towed the wooden boat into waters off Hakodate port. One of the crew has been hospitalized due to poor health and the other nine crew members remain aboard.

The coast guard found the crew dumping some appliances and other items into the sea on Nov. 29, and the coast guard later collected some of the objects.

Some of the crew had identification documents with their names and dates of birth.

At a press conference on Wednesday, Chief Cabinet Secretary Yoshihide Suga expressed concern over the issue, saying, "The government will pose stricter measures on maritime security to tackle suspicious ships and people."

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