The alleged incident took place at the Hilton Hotel in Auckland
Four England rugby players at the centre of allegations of sexual assault could be named by the Rugby Football Union to protect other squad members.
The RFU is considering setting up an internal inquiry, to be conducted by disciplinary officer Jeff Blackett.
"The team can't come back (from New Zealand) and nothing happens," Blackett, the RFU's Judge Advocate General, told the Sunday Telegraph.
"Something's got to happen and something has to be made public."
The England squad arrived home on Monday after losing the second Test in Christchurch on Saturday.
The police investigation into the alleged incident, which took place after the first Test in Auckland the previous Saturday, 14 June, is unlikely to continue unless the alleged victim lodges a formal complaint.
Unless others are named those innocent players may be tainted by association
RFU disciplinary chief Jeff Blackett
The four players were advised by the RFU's lawyer, Richard Smith QC, to decline being interviewed by police on the grounds that no such complaint has been made.
But the RFU is concerned that all the players in the squad could be affected by association with the allegations, regardless of their involvement.
"The consideration that there are a number of entirely uninvolved players - and that unless others are named those innocent players may be tainted by association - is a consideration we have to think about," Blackett said.
But despite the controversy, England's management agreed to allow players to go out in Christchurch after the 44-12 second Test defeat to the All Blacks following a team meeting with senior squad members.
Those players who opted to head into the city centre were accompanied by security guards and set a curfew of 0400.
"Some of the players did go out last night and we did talk about that as a group, whether it was appropriate in the circumstances," said Rob Andrew, England's elite rugby director.
"It is the end of a very long 12 months for these guys. It has been a tough experience out here, on and off the field. Some players went out, some didn't.
"We spoke to the senior players. We are not going to lock them in their rooms after a Test match. Players have got to take responsibility for their own actions, on and off the field.
"They went out last night, they were back at a certain time and they were having medical reviews at 8am this morning."
Police confirmed that all the England players were free to leave New Zealand as scheduled.
Andrew, who stepped in as tour manager for the squad in New Zealand in the absence of Martin Johnson, declined to comment on any potential disciplinary action.
But he will be meeting Johnson, who takes over officially on 1 July, this week on the squad's return.
There are lots of issues we are negotiating with the players' union at this point of time
Their primary focus will be deciding on the make-up of a 32-man elite player squad for next season, to be named on 1 July, the day Johnson takes over.
However, fly-half Danny Cipriani is unlikely to figure in the squad after sustaining a fractured dislocation of his right ankle in Wasps' Premiership semi-final victory over Bath.
But Johnson will also have an input into a new disciplinary code of conduct that all elite squad players must sign up to.
Under the existing code of conduct, the England players did not break any rules by staying out late after the 37-20 first Test defeat in Auckland.
But RFU chief executive Francis Baron said on Friday that they would consider banning players from bringing women back to their hotel rooms on future tours.
"We've never had a contract with the players before as the RFU and under the new agreement with the clubs, part of that is a new contract between the RFU and the players," Andrew told BBC 5 Live's Sportsweek programme.
"There are lots of issues we are negotiating with the players' union at this point of time."
Andrew also insisted the problems encountered on tour - both on and off the field - had not made him consider his own future.
"I am not going to consider my position," he added. "I am going to carry on doing the work that I am doing at the union. I am going to carry on with my position as the elite rugby director of the RFU."