A volunteer firefighter is a "hell of a mess" in intensive care after trying to evict an unwanted guest from a gathering in Martinborough.

Senior Sergeant Warwick Burr said a group of young people had been at a house in Broadway St, Martinborough on Saturday night.

A 25-year-old man, who was known to the group, arrived alone and uninvited and then refused to leave.

The group, largely girls, called on volunteer firefighter Peter Fisher to help remove the man and when he arrived up the gatecrasher allegedly attacked him.

Alcohol was not involved.

Fisher this morning remained in a serious but stable condition.

Martinborough Volunteer Fire Brigade chief fire officer Garry Jackson visited Fisher in hospital last night and said he was "hanging in there" but was still unconscious this morning.

"[His family] are thinking he might recover. They are waiting on results."

"He is a hell of a mess."

All injuries in the "brutal beating" were to the head and some teeth had been knocked out.

Fisher had been working at the Cool Change restaurant in Martinborough on Saturday night and it was understood he had been to the gathering to evict unwanted guests earlier in the evening.

About midnight, a second call came through to evict the 25-year-old.

"[Fisher] walked into a mine field," Jackson said.

"He is a guy who would not hurt anyone. He is not an aggro guy."

Fisher had almost 25 years in the fire service.

His partner and 13-year-old daughter were devastated.

Milton Haira, 25, of Masterton entered no plea when he appeared in Masterton District Court today charged with assault. He was remanded in custody until November 5.

Senior Sergeant Brent Murray, from the Wairarapa CIB, said the accused man lived near the house and had invited himself over.

As well as the serious assault charge that had been laid in relation to the alleged attack, some assault charges would also be laid in relation to alleged assaults on the other party-goers.

Police had several witnesses to talk to but were looking for information from anybody who was in the Broadway St area around midnight on Saturday night.

Anyone with information could phone Murray on 027 540 4394 or call Crimestoppers anonymously on 0800 555 111.

- © Fairfax NZ News