The captain, surnamed Wang, and his Togolese-registered cargo ship Hongtai were detained in February after a cable linking the Penghu archipelago and Taiwan was reported cut.

A district court in southern Taiwan found Wang guilty of violating the Telecommunications Management Act for destroying a submarine cable and jailed him for three years.

The court said Wang had ordered two crew members to lower the Hongtai's anchor into waters off southwestern Taiwan where he would have known anchoring was prohibited because it could damage the subsea cable.

The anchor's claw did not lodge in the seabed and the ship drifted.

The cable had been "completely severed" by the time Taiwan's coast guard intercepted the Hongtai and ordered the lifting of its anchor, the court said in the judgement.

Wang admitted he had been negligent but denied "intentional wrongdoing." He can appeal against the sentence.

The court said the evidence was sufficient to find Wang's "criminal conduct established", adding that the punishment was "a warning".

Taiwan's Chunghwa Telecom spent more than NT$17 million (US$578,000) to repair the cable, the court said.

Prosecutors had said Wang was the first Chinese ship captain charged with severing an undersea telecoms cable. The other seven crew members were to be deported without charge.

Taiwan has 14 international underwater cables and 10 domestic ones.

There have been a series of undersea cable breakages in recent years, with previous incidents blamed on natural deterioration of the wires or Chinese ships.

The coast guard said previously the Hongtai was among 52 "suspicious" Chinese-owned ships flying flags of convenience from Mongolia, Cameroon, Tanzania, Togo and Sierra Leone highlighted for close monitoring.