The New Zealand under-20 rugby player at the centre of a rape allegation is shattered by the claim made against him, says rugby union boss Steve Tew.

Tew told reporters in Wellington the unnamed player was "very upset" after he was made aware of the complaint made by a 22-year-old woman in South Africa.

He says the New Zealand Rugby Union is assisting with a police probe into the claim that a player raped a woman in the team hotel in Cape Town in the early hours of Saturday.

"We are dealing with a very serious situation. We are providing our team and particularly the player involved with appropriate support, but we are also co-operating fully with any inquiries," he said.

The player, one of the 28-strong squad which lost IRB world championship final 22-16 to the hosts on Friday, had provided a DNA sample and a statement to police in South Africa.

"It's disappointing, but let's be clear, we're still dealing with an allegation, no charges have been laid, no one has been detained, no one has even been to a police station," Tew said.

"He's given us his version of events and the police are trying to piece together what might have happened.

"They're the experts and we'll leave them to do their job."

Police spokesman Colonel Vishnu Naidoo said the alleged victim was having trouble remembering anything about the incident.

The team was allowed to leave South Africa as scheduled and arrived back in New Zealand on Sunday evening.

Tew says they had not heard anything further from South African authorities since returning home.

The New Zealand government had been briefed on the issue, but Tew says they did not require the help of consular officials based in Pretoria.

Prime Minister John Key says he expects New Zealanders travelling overseas to follow the laws of the countries they are in.

"I'm not in any position to comment about whether this person has or hasn't, but simply that's my expectation. But if there's a case to answer then the person will need to deal with that issue," he told reporters.

The rugby union would not be naming the player, who had been drinking on the night, to protect his privacy but accepted it would cast doubt on the entire squad.

The player was likely to face disciplinary action for breaching team protocols by allowing a woman into his room, Tew said, but would not speculate on what the penalty may involve.

NZ Newswire

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