A detective sergeant who failed to properly investigate a 14-year-old girl's claims she had sex with an older man has been given a written warning.

Thames Valley Police said the officer was found guilty of misconduct following a two-day hearing that concluded yesterday.

The force said in January 2012 the officer received an allegation by the girl that she had had sex with a 17-year-old or 18-year-old male in Cowley, Oxford.

The officer was made investigating officer for the case but failed to contact the girl or her father.

He then failed to hand the case over when he was seconded to another operation in February 2012.

In November 2013, the same girl reported that in the summer of 2012 she had been the victim of a rape incited by the same man, Omid Ali, who was later convicted of rape and of engaging in sexual activity.

Deputy Chief Constable John Campbell said: “After carefully considering all of the evidence the Misconduct Panel concluded that the officer’s conduct did amount to gross misconduct and that he was in breach of the following Standards of Professional Behaviour namely duties and responsibilities and discreditable conduct.

"The officer in this case has been issued with a final written warning and was left in no doubt about the seriousness of his actions.  

“The officer involved has a good track record within the Force and has worked hard to bring offenders, particularly in sexual offence cases, to justice.

"He is aware that in this case his conduct was unacceptable and that he has let the victim down.”