A New Zealand man almost bled to death when he was seriously wounded by arrows as he tried to save his girlfriend from being raped by a tribesman in Papua New Guinea.

Details emerged last night of how Matthew Scheurich, 28, pulled the two arrows from his torso as he and his 29-year-old girlfriend fled for their lives.

The attack reportedly happened in a remote village in western Papua New Guinea after the tribesman took a liking to Mr Scheurich's French girlfriend and wanted to marry her.

When Mr Scheurich stepped in to protect her, the tribesman attacked him with arrows and bashed him in the head with a rock.

"The spears [arrows] narrowly missed the man's vital organs," Gilles Cote, Catholic Bishop of Daru-Kiunga, told the Cairns Post. "He lost a lot of blood. It's a miracle he survived."

Mr Scheurich's girlfriend was sexually assaulted and was also bitten, cut, scratched and badly bruised.

She set off the couple's emergency locator beacon to raise the alarm.

They escaped their attacker and were looked after by the bishop's church members in the village of Suabi before being flown to the port town of Kiunga.

Dr Josette Docherty, an Australian doctor working for the Australian Doctors International agency, said her first glimpse of Mr Scheurich was of him lying on the stretcher "deathly pale" and in pain.

One arrow had passed through his ribs, under his liver, through the wall of his stomach and stopped just short of his aorta. The other had split an artery as it travelled into his chest.

Dr Docherty said an x-ray showed Mr Scheurich's chest was half-filled with blood and he needed surgery to repair the wounds, as well as a blood transfusion.

He needed 1.5 litres of blood, including half a litre from Dr Docherty's partner, medical volunteer Allan Mason.

Mr Scheurich, a graphic designer from Waikato who now lives in Melbourne, was in Papua New Guinea with his girlfriend, an anthropologist who was working towards her doctorate with a tribe near Suabi.

In a March blog entry, Mr Scheurich said he had "gone to Papua New Guinea to live in the jungle, be back in six months' time or so".

After the incident, Mr Scheurich's girlfriend stayed at his side, partly because there was only one staff member on duty at night in the 25-bed ward in Kiunga.

Dr Docherty returned early the next morning after being woken by the woman, who was concerned about Mr Scheurich's condition.

He was stable but needed oxygen throughout the day. A local plane flew him and his girlfriend to the capital, Port Moresby, and then to Cairns Base Hospital last Tuesday.

He spent a week before being discharged and he returned to Melbourne on Tuesday.

Dr Docherty said the attack was "an extremely unfortunate and rare incident" in impoverished Papua New Guinea.

And an Australian Doctors International spokesman said the attack was the first case of hostility the agency had heard of in its nine years in the area.

"Generally we find the people warm, hospitable and proud to share their culture with foreigners."