A man who had sex with a 15-year-old Orthodox Jewish boy has failed to clear his name in the Court of Appeal.

Najibullah Ahmadzai, 25, of Walthamstow, was found guilty at Snaresbrook Crown Court in June last year of sexual activity with a child.

Deemed a danger to the public, he was sentenced to indefinite imprisonment for public protection and ordered to serve at least three-and-a-half years behind bars before he could apply for parole.

He had sex with his victim, a member of the Orthodox Jewish community, after they met at a Stamford Hill internet cafe, where Ahmadzai worked.

At the Court of Appeal, lawyers for Ahmadzai argued that his conviction was “unsafe” because he was acquitted of other charges relating to the victim, and the victim’s brother.

Judges were told that the “inconsistencies” in the jury’s verdicts rendered Ahmadzai’s conviction unsafe, and it should be quashed.

However Lord Justice Keene, sitting with Mr Justice Blair and Judge John Rogers QC, said that, although it may have been “surprising” that Ahmadzai was found guilty on one count but acquitted on others, it did not mean his conviction was “unsafe”.

During their deliberations, the jury had asked the judge whether they could convict if Ahmadzai had a “reasonable belief” that his victim was over the age of 16.

His lawyers argued that the jury must have come to the conclusion that Ahmadzai had believed his victim to be over 16 on one occasion when they engaged in sexual activity, but not another, and that was inconsistent.

The court heard that Ahmadzai had had sex with his victim in either 2006 or 2007 after asking him to the back of the internet cafe.