BECKY Godden vowed to her mum she would "come home when she was clean" in their last conversation before she was allegedly killed by Christopher Halliwell.

Halliwell, 52, is alleged to have strangled Rebecca Godden, 20, and buried her in a remote field in Eastleach, Gloucestershire, in 2003.

He denies a charge of murder and is on trial at Bristol Crown Court.

Karen Edwards last spoke to her daughter on December 16, 2002, after picking her up from Swindon Magistrates' Court.

A statement by Mrs Edwards read by prosecutor Nicholas Haggan QC at Bristol Crown Court said she had moved away from Miss Godden's father John Godden when her daughter was about three.

She described how her daughter, a "happy little soul", had fallen into drug addiction and started running away from home aged 15.

The family assumed she was working as a prostitute as she had money to buy drugs but never "mentally accepted it", she said.

Age 16, Miss Godden managed to get clean from drugs and started working at Reader's Digest.

"I felt so relieved and thought the bad times were over," Mrs Edwards' statement read.

"After about a year of being clean, Becky began socialising with her old circle of friends and got dragged back into the world of drugs.

"She must have been 19 years of age when she was in rehab for five weeks. It seemed to clean her up for a while but it didn't last."

On December 16, 2002, Mrs Edwards collected her daughter from the court.

"She had conditions to stay at my house," her statement said. "I wanted her to have a tag but it was denied.

"On the way home she said she wanted to see her boyfriend. She begged me and said she would just be half an hour.

"After a while she came back out and told me she wanted to stay longer. I became firm with Becky as I knew the best place for her was at home.

"When she was begging me I told her she had two choices - get into the car with me and go home or take her bag and not come running back.

"Becky took her bag and told me she would come home when she was clean. That was the last time I saw her."

The family reported her missing to police but she was not dealt with as a missing person, the court heard.

"It was just a waiting game," Mrs Edwards' statement said.

"We talked about her as though she would turn up one day.

"I never thought she wouldn't be coming back. Then we heard about remains at Eastleach on the news.

"I feared the worst but I never thought deep down that it was Becky.

"It seems to me that Becky went off the rails at a time of her life that was stable. I ask myself where it all went wrong."

The last sighting of Miss Godden is believed to be her getting into a taxi outside Destiny And Desire nightclub in Swindon in January 2003.

Rebecca Boast, then 17, had been in the club with Miss Godden, who she had met there a few nights before.

"I quite liked her so I wanted to know her," Ms Boast said.

"She said her name was Becky Edwards and she said it quite happily as if she was having a good night.

"She was very friendly and happy. She was wearing a fur coat. I asked her how she was able to afford it.

"She replied that she was a prostitute."

Ms Boast said she would meet Miss Godden in the nightclub and did not have her mobile phone number.

"The last time I remember seeing Becky we had been in Destiny And Desire, we had danced, smoked, chatted," she told the jury.

"She never spoke much about her private life, she just wanted to have a giggle and a dance and she kept telling me these jokes."

The pair had a cigarette outside the nightclub when it closed and Ms Boast saw a taxi pull up.

"Becky went over to the taxi," she said.

"The driver wound his window down. Becky leant into the window. She was speaking to the driver.

"She came back over to me and my boyfriend for a while and was smoking again, we were really bad chain smokers.

"Then she went back over to the car, the taxi, and she leant over the window and she appeared to be rowing with the driver.

"I could hear raised voices and Becky was yelling."

Ms Boast said Miss Godden came back to her and seemed stressed.

"A few minutes later she said that she was leaving and she went and got into the back of the car, behind the passenger seat," she added.

"It drove away."

Halliwell is currently serving a life sentence with a minimum term of 25 years after admitting stabbing and strangling Sian O'Callaghan, 22, in 2011.

The trial, expected to last for four weeks, continues.