Kiwi who was in Syria is safe and well - family

Prime Minister John Key would not reveal what forms of contact the Government had with the expat New Zealander. Photo / APN

A New Zealander who was known to have been in Syria is safe and well in California, according to his family.

A New Zealander who Prime Minister John Key said the Government had "lost contact" with is believed to have been killed fighting in Syria.

The unidentified man would be the first New Zealand casualty in the Syrian civil war, where a small group of Kiwis has joined the rebel forces.

Chinese-born artist Weiming Chen has a New Zealand passport and has travelled to Syria to fight alongside the rebel forces.

His nephew, Alexander Karsten-Chou told Radio New Zealand that Mr Chen had been in touch with family from California, so they knew he was alive and safe, after news broke of a New Zealander being killed in Syria.

Mr Karsten-Chou said his uncle had been to Syria three times, and was driven by his strong anti-communist and anti-China beliefs.

"Our entire family is quite anti-Communist," he said.

"For the latter part of his life all he has been concerned about is the right to vote, democracy, freedom. So I think for someone like him who is so focused on this it's not unusual at all."

A Syrian Government representative at the United Nations in New York said on Sunday that a New Zealander was among the foreign "mercenaries"and "terrorists"who had died while fighting government troops.

Mr Key said on Tuesday that he was told in January there was "a high probability"a New Zealander had been killed while fighting in the region. He could not rule out other New Zealand deaths in Syria.

There was no firm evidence of the man's death but "we've lost contact with him and his family has lost contact with him", the Prime Minister said.

"We haven't had any evidence since January that the person's alive, and on that basis there is a reasonably high probability the person has died."