A woman whose husband was jailed today for murdering their 15-year-old daughter 10 years ago in an "honour killing" is living in fear of reprisals after she gave devastating evidence against him.

Tulay Goren was killed in January 1999 for running away from home to live with her boyfriend, a fellow Turkish Kurd twice her age whom her family disapproved of because he was from a different branch of Islam.

Today, at the end of a dramatic and emotional 11-week trial, Mehmet Goren was given a life sentence, with a minimum of 22 years, for killing his daughter after kidnapping, drugging and tying her up. Her remains, which police believe were buried in the family garden temporarily, have never been recovered, making this one of only a handful of murder convictions secured without a body.

The prosecution claimed Mehmet's brothers Ali, 55, and Cuma, 42, helped him in the murder after a "family council" decided that she and her forbidden lover must die. But the Old Bailey jury were not convinced and cleared the brothers of any involvement in her murder.

Tulay's mother Hanim, whose testimony against her husband was crucial to the prosecution, was too afraid to attend court for the rest of the trial. Last week police installed additional security measures in her home and that of her surviving daughter, Nuray, also a prosecution witness. Yesterday, Nuray praised her mother for testifying. She said: "No one should fail to realise what this means within our culture. These people do not forget."

She added: "For my father, I have only one request. 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."

Experts have said the breach of the code of honour, or namus, that detectives believe led to Tulay's killing could also apply when a woman speaks out against her husband.

The case marked the first time prosecutors have used expert witnesses in an "honour" crime. They described how the system worked among Turkish Kurds and highlighted features of the Goren case – such as the loss of her virginity to her boyfriend, a loss of family honour that triggered the murder – which paralleled similar murders in Turkey.

Police believe there are 12 "honour killings" a year in Britain, and a quarter of the victims are under 18. Police and prosecutors introduced new measures to protect and punish perpetrators in the wake of public criticism of failings in the case of Banaz Mahmod, who sought police help before she was killed by her father and uncle in 2006. Risk assessment measures identifying cases where victims may be vulnerable are now flagged up in police stations, police receive training in "honour" violence, and there are now prosecutors who specialise in the crime.

Sentencing Mehmet to life, Mr Justice Bean told him that his attempts to portray himself as an enlightened family man had not worked. "Your enigmatic smile conceals a violent and dominating personality," the judge said. "The victim was a child of 15 with her whole of her life before her. You were in a position of trust as her father. You planned her murder with considerable care."

Speaking about the day Tulay was killed, the judge went on: "You instructed your family to leave the house, telling her eight year-old brother to kiss her goodbye because he would never see her again. I was not surprised to be told that this moment has haunted him ever since."

An "average, normal or unexceptional murder" carries a 14-year sentence but the judge said Tulay's killing had many aggravating features, including planning, and was similar to racially or religiously aggravated killings.

Detectives came to believe that Mehmet killed his daughter as early as March 1999, when Hanim told them of her suspicions. But the Crown Prosecution Service advised against charging him because they could not rule out the possibility that she was still alive. At that time "honour killing", particularly in the Turkish and Kurdish community, was an alien concept to police and public. But when the case was re-examined in 2007, it followed the successful prosecutions of similar murders. In 2003 an Iraqi Kurd, Abdulla Yones, was jailed for life for killing his 16-year old daughter, Heshu, and in 2007, the father and uncle of Banaz Mahmod were given life imprisonment for her murder.

Gerry Campbell, of the Met's violent crime directorate, said the lessons learned had "galvanised us to know and understand honour-based violence".