Green Party co-leader Russel Norman has laid a complaint with police alleging he was assaulted by Chinese security guards accompanying China's visiting Vice-President Xi Jinping.
The remainder of the day's schedule was hurriedly changed as a result of the incident, which the Prime Minister describes as very disappointing.
Dr Norman has also called for the detention of the Chinese officials involved before they leave the country on Saturday.
The Green MP was taking part in a peaceful protest demonstration on Parliament's forecourt. When Mr Xi arrived for a meeting with Speaker Lockwood Smith, about a dozen guards surrounded Dr Norman and tried to elbow him out of the way.
They put an umbrella over him and a Tibetan flag he had been holding was grabbed and stomped on the ground.
Dr Norman says his hand was cut when it was stood on while he was trying to get the flag from under their feet.
He says it's outrageous that Chinese security can come to New Zealand and push around an MP on Parliament's grounds because he was standing up for democracy and freedom.
Soon after, the venue for a meeting between Mr Xi and Opposition leader Phil Goff was changed from Parliament to a nearby city hotel.
Prime Minister John Key, asked to comment on the incident, says it's very disappointing that it happened and that he hopes it won't overshadow the Vice-President's trip.
He says he doesn't know the full details of what happened, and it's really now in the hands of police and the Speaker of the House.
A spokesperson says that if the Speaker receives a complaint he will investigate it.
The Wellington area police commander, Inspector Peter Cowan, says Dr Norman's complaint will be assessed and investigated as quickly as possible.
He says any investigation will include speaking with witnesses, viewing video of the event and liaising with the Speaker.