Voice of America(VOA) reports that North Korean coal held at an Indonesian port since last year over suspected illegal transshipment is on its way to Malaysia on board a foreign-flagged vessel.

Citing ship tracking data as well as local sources, the report said Tuesday that a vessel carrying the coal was observed passing by the southern tip of the island of Borneo late Monday night.

According to an annual report issued by the UN Security Council's North Korea sanctions committee, a vessel named "Wise Honest" was detained by Indonesian authorities around April last year for carrying 25-thousand tons of North Korean coal.

VOA said this vessel was taken to an area near the Indonesian city of Balikpapan last month where the coal was unloaded and then transferred to a Panamanian-flagged vessel operated by a Vietnamese shipping firm.

VOA said the ship is expected to reach Malaysia as early as Wednesday.