The father of a 15-year-old schoolgirl who disappeared without trace 10 years ago has been jailed for a minimum of 22 years after being found guilty of murdering her in a so-called "honour killing".

Tulay Goren was killed on 7 January 1999 after falling in love with Halil Unal, a fellow Turkish Kurd twice her age, and running away from home to live with him.

Her family disapproved because he was a Sunni Muslim while they were Alevis, a different branch of Islam.

Police believe Tulay's body was buried temporarily in the back garden of the family home, but her remains have never been recovered.

Her father, 49-year-old Mehmet Goren, from Woodford Green, north London, was convicted of her murder in an Old Bailey trial and jailed for life with a minimum of 22 years.

His older brother, Ali, and younger brother, Cuma, were both cleared of the charge.

The family, originally from Elbistan, in south-eastern Turkey, adhered to the code of namus, or honour, practised in many rural communities there.

Tulay's mother, Hanim, gave evidence against her husband of 30 years, telling the jury how she had seen her daughter tied up the day before the murder.

At one point during the trial, she turned to him in the dock and said: "Look at my face. What did you do to Tulay?"

Mehmet killed his daughter to restore the namus breached when she ran away to live with Unal, the trial was told.

Police paid tribute to Hanim's bravery, with Detective Inspector Dave Corby, who led the investigation, saying: "She wanted justice for her daughter. She has always wanted that."

It was her decision to tell police the truth, two months after Tulay died, that first alerted them to the fact that the missing schoolgirl had been murdered.

Hanim had initially gone along with her husband's lie that the girl had run away but, under questioning in March 1999, decided to tell police what really happened.

"They said: 'What did you do to Tulay? Did you do it?' I couldn't take it any more and I revealed. I told the truth to police then, everything," she said later.

Her interview led to police digging up the Gorens' back garden for the first time, and Hanim went back to tell them more of what she knew in April and June.

In 2001, the schoolgirl's father was convicted of grievous bodily harm for an axe attack on Unal outside the Thatched House pub, in Leytonstone, and served three years of a five-year jail sentence.

It was only recently that police were able to pursue the murder charge against him.

The case is the first time the Crown Prosecution Service has used expert witnesses in "honour" crimes.

After the case, Nuray Guler, Tulay's older sister, urged her father to tell the family where she was buried.

"For my father, I have only one request," she said. "I ask that he finally discloses the whereabouts of my sister.

"I wake up at night wondering where Tulay may be. In quiet moments during the day, I ask myself if she suffered or knew what was in store for her.

"I ask that he put an end to the nightmares that haunt us and allows us to retrieve Tulay in order that she may rest in peace."