Former All Black Robin Brooke is facing legal threats over allegations he assaulted a teenager in Fiji, amid revelations that another rugby star was with him at the luxury resort.

An Auckland schoolgirl claims Brooke, 43, grabbed her backside twice while she was poolside at the Hilton Fiji Beach Resort and Spa on Denarau Island on New Year's Eve. Another teenager, a boy, alleges Brooke assaulted him as he tried to intervene.

Fiji sergeant Suliano Tevita said a decision on whether to charge Brooke, who played 69 matches for the All Blacks, had not been made. Two officers were still investigating.

But 17-year-old Jordan Whittaker, who claims Brooke threw him on a deck chair and grabbed his throat when he stepped in to protect the 15-year-old girl, doubted charges would be laid.

He and his father have instructed a lawyer to file civil proceedings.

Whittaker's lawyer Peter Lowing OBE advised him not to comment. Lowing also refused to speak about the case.

However the Herald on Sunday obtained an email sent by Lowing to the girl's mother, saying Sydney lawyer Stuart Littlemore QC was helping with the matter.

"On the advice of Mr Littlemore we would initially write to Mr Brooke asking for a written apology and an amount of money as compensation for the assault. In all probability Mr Brooke would welcome the opportunity to come to some arrangement without allowing a writ to be served," Lowing said in the letter.

"At the same time in respect to Jordan we are looking at the possibility of issuing the process in NZ (if need be) although this may not be available due to the rules regarding private international law."

Brooke did not return calls from the Herald on Sunday this week. There was no sign of him or his wife Hayley at their Tauranga home. They own a New World supermarket in Tauranga, but a staff member said Brooke was on holiday until the end of the month.

His agent Sara Tetro also failed to respond to requests for comment. Tetro, the host of New Zealand's Next Top Model, is married to ex-All Black star Craig Innes, a former team-mate of Brooke.

Innes confirmed yesterday he was with Brooke in Fiji. He said Sara "was actually sick in bed".

"I cannot comment on anything at all because the investigation is ongoing," he said. "There are some crazy things going around ... I appreciate the chance to clear this up but until everything is put to bed, I can't comment."

In his letter, Lowing said he did not expect Brooke to be charged - one reason being his "sporting background".

"If they did charge Mr Brooke he would have to be in the country ... We doubt that Mr Brooke would return voluntarily and the prospect of extradition is highly unlikely."

The mother of the 15-year-old girl said she had been invited to join Whittaker in his civil proceedings. She spoke to her lawyer "at length" about it and would speak to her daughter before a decision was made.

"Maintaining the privacy of our daughter is paramount. That's why we are taking legal advice. We are really keen to support Jordan, we are indebted to him," she said.

"We are not interested in his [Brooke's] money. We won't accept any money. He actually hurt our daughter. It wasn't just a pinch on the bum - he physically hurt her and she was doing nothing to provoke that.

"He has daughters of his own. How would he feel if some stranger hurt one of them? As a parent, I am sure his daughters are precious, just like ours. And the thought of anyone hurting them ... he needs to front up and say he is sorry."

The woman said she remained angry.

"I thought at least his agent would have contacted us.

"I expected to hear from Brooke this week, I feel a bit naive for that, really. I thought he might offer some sort of explanation - whatever it is."

She said it had been devastating hearing and reading comments about her daughter "asking for it".

"She's 15 - and she looks 15. She's not one of these girls who wears make-up and that sort of thing. She has no incentive to make anything up - she didn't even know who he was. He was just an older man to her. In fact, he's not even a star, he's history. She just thinks he's a creepy old man."

Brooke's business partner Gavin Austin, from Whangarei, had not heard from Brooke and did not know where he was.

Another associate, who didn't want to be named, said it was likely Brooke had been advised not to comment publicly until the police investigation was over.

"Behind closed doors he's going to be ... dealing with the issues. My opinion is that at some stage he will front up. But he could be waiting to hear about the charges. Knowing him, he will front - but all in good time."