JUDGES have doubled the 'unduly lenient' prison sentence given to a disgraced former teacher who groomed a pupil online.
Luke Fisher was jailed for 18 months earlier this year after admitting a string of offences against his 15-year-old victim.
But the case against 28-year-old Fisher - who taught history at Holmer Green Senior School - was referred to the Court of Appeal, where judges doubled the length of his sentence to three years.
Fisher, of Pinkneys Drive, Maidenhead, had a last minute change of plea to guilty on what would have been the first day of his trial at Aylesbury Crown Court on April 1.
He admitted three counts of sexual activity with a child and one of meeting a child following sexual grooming and was handed an 18 month sentence by Judge Francis Sheridan.
But an Appeal Court judge said Fisher's punishment was "not merely lenient, but unduly so".
Passing judgment Lord Justice Treacy, who made the ruling alongside Mrs Justice Lang and Judge John Bevan QC, said: "In our assessment, this case would have merited a term of around four years after a trial.
"We make some allowance against that for the guilty plea, albeit late, the accepted remorse and his lack of previous convictions.
"In the circumstances, the least sentence that can be passed for these offences is one of three years."
The court heard Fisher, who watched the appeal hearing via a video link from prison, invited the girl to his home after contacting her through Facebook before touching her sexually.
He contacted her over a three month period, with the messages becoming increasingly sexually explicit over time.
In a victim impact statement the girl - who cannot be named for legal reasons - said she had lost social confidence as a result of the incidents and had become anxious.