Lawyers for former All Black Robin Brooke, who is facing accusations from a teenage girl of sexual assault, say he is distressed by the situation but can't comment on it until an investigation is complete.

The 15-year-old Auckland girl said Brooke had twice grabbed her backside while she was pool-side at a resort at Denarau, Fiji, on New Year's Eve.

The girl's 17-year-old Australian friend, Jordan Whittaker, said when he tried to intervene he was grabbed around the throat by Brooke and threatened. His family have reportedly started civil proceedings against Brooke.

Fiji police launched an investigation into the allegations and said today their inquiries were ongoing and there were no new developments.

A statement today from Brooke's Tauranga-based law firm, Adams and Horsley, said media attention had been intense, but Brooke had been strongly advised not to comment because of the investigation.

"It is important not to jeopardise the integrity of that process. In addition, others have chosen to initiate a formal legal process.

"Mr Brooke is naturally distressed by the situation, has made himself freely available to the authorities, but as you will appreciate cannot comment publicly," the statement said.

The mother of the girl said at the weekend the family was considering joining civil proceedings against Brooke, who owns a New World Supermarket in Tauranga.