It said the suspension was based on "alleged criminal acts" referred to in a police report regarding the "accommodating, utilising, processing and refining, transporting (and) selling" of minerals from sources without permits.

A trade ministry source said the suspension came into effect on Oct. 16.

A spokeswoman for state-owned PT Surveyor Indonesia declined to provide immediate comment. ICDX also declined to comment.

Only one 5-tonne lot of the most active TINPB300 tin contract was traded on Wednesday and none changed hands a day earlier, data on the bourse's website showed.

On average, 46 lots had traded daily since the beginning of August, the data showed.

Indonesia is the world's top tin exporter, with shipments from January to September at 62,896 tonnes, up 13 percent year on year.

London Metals Exchange (LME) tin was the only metal trading in positive territory on the bourse on Thursday, up 0.45 percent to $19,165 a tonne as of 1130 GMT, with gains supported by the ICDX moves.

Asked about the police report, National Police special crimes director Fadhil Imran said his office was carrying out a "comprehensive investigation" of tin mining in Bangka Island, one of Indonesia's main sources of the metal.

Imran declined to provide details on the investigation or to confirm that Surveyor Indonesia was the subject of its probe.

Surveyor Indonesia provides verification services to industries and the government and had 1,950 employees as of 2017, its shareholder meeting report for that year showed.

The company's suspension would not disrupt Indonesia's tin trading, said Indrasari Wisnu Wardhana, chief of the Commodity Futures Trading Agency (COFTRA), part of the Trade Ministry.

"There is only a little stock with verification from Surveyor Indonesia," Wardhana told Reuters.

Indonesia's biggest tin producer, state-owned PT Timah, said it was not affected by the suspension as it does not use Surveyor Indonesia for origin verification.

(Reporting by Bernadette Christina Munthe; writing by Fergus Jensen; editing by Kenneth Maxwell and Jason Neely)

By Bernadette Christina Munthe and Agustinus Beo Da Costa