THE father of an abuse victim has told a jury at Exeter Crown Court how he believed the sex attacker's policewoman girlfriend tried to talk him out of reporting the assault to the authorities.

PC Sarah Cohen visited the parents just hours after they learned their 14-year-old daughter had been groped during a sleepover party at an Air Training Corps hut in Devon.

The drunken attack was carried out by Cohen's boyfriend James Reading, who organised the unofficial party, the court was told.

Launceston-based Cohen is on trial accused of perverting the course of justice by trying to persuade the parents of the teenaged girl not to report his attack.

The victim's father told the jury Cohen came to his house on the night the allegations came to light and warned them their daughter would have to re-live her ordeal in court if a complaint was made.

She also told him she would arrange treatment for Reading if they did not report his assault on their daughter to the police.

Cohen, aged 36, from Lifton, denies two counts of perverting the course of justice in the two days after Reading sexually assaulted the girl in November 2011.

She was Reading's girlfriend at the time and was also the flight lieutenant in charge of the ATC squadron where he was the flight sergeant.

The jury has been told that Sgt Reading, aged 37, has been convicted and jailed for the sexual assault.

The prosecution allege she intervened to prevent him being arrested after he armed himself with a hunting knife, drove while drunk to Meldon Dam, crashed the car and threatened suicide.

The girl's father said he had been at the sleepover party at which the assault happened but had been asleep after going on a pub crawl with Reading.

He was unaware that other male cadets had thrown Reading out of the hut, leading to the incident at Meldon, and his first knowledge of either incident was when Cohen came to the hut on the Sunday morning to send the cadets home.

He saw her again the next evening when the squadron held their weekly parade and she informed him about the assault on his daughter after calling him into her office.

He said: 'I cannot describe how a father feels when his daughter has been sexually assaulted. I was shocked. She was saying: "That's my Jamie. That's my Jamie" but did not seem to be that agitated. She was quite calm.

'I spoke to my daughter in the car on the way home but she did not say a lot. She came in on herself. I told my wife and we did not know whether to report it.'

He said they rang Detective Superintendent Michelle Slevin, who they knew socially, who advised them to report the assault to the police and they were planning to do so the next morning, when they were called by Cohen at around 11pm.

She came to their house and remained for about 90 minutes and told them Reading had made suicide attempts in the past.

The father said: 'She said she was in a dilemma because she was wearing three hats, her ATC hat, her girlfriend hat and her police hat.

'She said each of the hats had their own piece of advice. She said the easy one was a squadron boss because she had a duty to the cadets so she should report Reading to the police.

'Next came the girlfriend hat. She said if we did not report it she would make sure Jamie got treatment and never worked with cadets or children again.

'She said she had had him sectioned and taken to hospital.

'The third hat was her police hat. She said we were quite within our rights to report it to the police but we should bear in mind it would be a very difficult and trying time for our daughter.

'She said she would have to go through the courts and make a statement as a witness. She made it clear it would not be a very nice time for her and she would have to relive the assault again.

'She did not tell us to report the matter to the police or say she would report it to the police.

'I thought at the end we had the conversation so she could deliberately talk us out of reporting it to the police.'

Cohen denies all the allegations.

Her case is that she acted properly in going to Meldon to defuse a critical situation and that she could not have tried to influence the girl's parents because they had already reported the matter to another officer.

The trial continues.