A report from Vanuatu says the Prime Minister, Serge Vohor, has been accused of assaulting the Chinese Ambassador in the latest stage of the row over Mr Vohor's unilateral recognition of Taiwan.
Beijing's newly installed envoy to Port Vila, Bao Shusheng, said he was punched on the shoulder by Mr Vohor.
He told the AFP newsagency the incident occured when he went to parliament to see Mr Vohor to complain the flag of Taiwan was still flying in Port Vila, after it was supposed to have been taken down following a ruling by the Council of Ministers.
Mr Shusheng says he was shocked by the incident, but decided not to make a formal complaint to police about it.
The row over China and Taiwan started when Mr Vohor went secretly last month to Taiwan, where he signed an agreement to recognise the Taipei government.
But the Council of Ministers, which is effectively Vanuatu's ruling body, then revoked the deal and decided to revert to recognition of Beijing under the One-China policy.
Vanuatu's Supreme Court is expected to make a ruling today on whether a vote by MPs on a motion of no confidence in the government can go ahead.