HE is the monster serving a prison term for a series of horrific rapes.

Gareth Warburton also subjected his victim to a frightening assault in which he beat her about the head.

Today, on what is his 47th birthday, one of the top judges in the country has ordered the dad of six to spend an extra seven years behind bars.

Lord Justice Leveson, the high court judge who oversaw the controversial review into press regulation, has ordered Warburton’s sentence be more than doubled because it did not reflect the gravity of what he had done.

At London’s Court of Appeal Lord Leveson spoke of his “astonishment” that such a lenient jail term had been handed down to him at Southampton Crown Court and ordered it be increased from six years to 13.

It’s thought to be one of the biggest increases of sentence ever passed for a case in Hampshire and has been welcomed by police chiefs and the victim as “justice”.

Warburton was initially arrested on the afternoon of July 9, 2012 following allegations of assault by a woman who called police.

Following an investigation he was charged with nine counts of rape, of which he was later acquitted of three of the charges following a trial at crown court.

Jurors also found him guilty of one offence of assault when the ten-day case came to an end on March 27 this year.

Unemployed Warburton, of East Boldre in the New Forest, had always denied the charges.

Astonishing The court heard how he had previous convictions dating back before 2004, which were described as minor and included motoring offences.

Giving his ruling Lord Justice Leveson, sitting with two other judges, told the court: “I think this is an astonishing sentence.”

He then ordered that Warburton must now serve 13 years behind bars for his crimes.

Det con Jonathan Davies, from Southampton Police’s public protection unit, said: “It took the victim a great deal of courage to come forward and report these matters to police and to go through the subsequent court process.

“Hampshire Constabulary is pleased to have demonstrated a zero tolerance attitude to such violence and to have brought this offender to justice. Both we and the victim are delighted that the new sentence reflects the gravity of his crime.”

Simon Brenchley, head of CPS Wessex Rape and Serious Sexual Offences (Rasso) Unit, said: “We welcome the decision of the Court of Appeal to increase Gareth Wyn Warburton’s sentence.

“When the sentence was imposed the CPS felt that it did not reflect the seriousness of the evidence that was presented to the jury and asked the Attorney General, Dominic Grieve QC MP, to consider whether the sentence imposed was unduly lenient. He referred the case to the Court of Appeal, who agreed that the sentence was unduly lenient.”

The Attorney General, Dominic Grieve QC MP said: “The original sentence of six years did not reflect the fact that this case concerned repeated offences committed over a number of years.”