Ex-Air Force sergeant found guilty of rape

Robert Richard Roper was found guilty at Auckland District Court. Photo / File

An ex-Air Force sergeant has been found guilty of more than 20 sexual charges against five girls, and police have revealed more women have come forward since his trial began.

Robert Richard Roper, 69, went on trial at Auckland District Court last month on 23 sex and violence charges stemming back to the 1970s and 1980s when he worked at the Royal New Zealand Air Force base in Hobsonville in the transport division.

Late last night, a jury found him guilty on 21 of those charges - all the sex allegations.

He was acquitted on counts of male assaults female and assaulting a child.

The officer in charge of the case Detective Bryony Brown said that since Roper's name was published at the start of trial, other women had been referred to police.

"I'm not willing to go into numbers at this stage but what I will say is that we encourage anyone who has been a victim of sexual offending to talk to us," she said.

Roper's offending came to light only at the end of 2012 - 23 years after leaving the Air Force - when the first victim came forward saying he began abusing her at the age of 6, progressing to rape as regularly as once a week when she was a teenager.

By May 2013, police charged him, as friends of the first woman gradually approached police with similar statements.

One victim told the court about a night when Roper offered her a lift home.

He kissed and groped her as soon as they were in the car, before driving her to an area known as "the bombing range" at the base.

Roper reclined her seat and locked the doors as she tried to escape.

He bound her hands with the seatbelt and raped her, the court heard.

Ms Brown said the victims were "very relieved" with the guilty verdicts.

"This was obviously a very difficult time for them and we are very grateful to the victims in this. Many of them were understandably very traumatised by Roper's offending and it is because of their actions of coming to us to report his offending that we were able to put him before the courts and get this result."

Roper will be sentenced in February.