A ruthless "conman and paedophile" who was jailed for bigamy and for swindling his vulnerable girlfriend deserved every day of his five-year sentence, top judges ruled today.

American William Allen Jordan received the jail term at Oxford Crown Court in December last year after admitting bigamy, obtaining funds by deception, failing to register as a sex offender and illegal possession of a stun gun.

Jordan, who had moved from Blackburn to Oxford before he was caught, was described by top judge, Mr Justice Royce, today as a "real conman of the worst kind".

His crimes were "desperately mean", he told London's Criminal Appeal Court.

The 42-year-old, who received a 15-month sentence in 1997 for indecently assaulting a schoolgirl, wed his first wife, Julie Cunningham, in 1992, going on to have five children by her.

Ten years later - unknown to his first wife - he married Mary Turner Thomson, who gave birth to two more of his offspring and lives in Edinburgh.

And in 2005, Jordan began a relationship with a young Blackpool woman, Denise King, from whom he borrowed £4,500, despite her pleading that the cash was "all she had".

Jordan promised Miss King he would repay the cash, but she never saw a penny of it again.

He went on to use her credit card to make illegal payments at a Mercedes Benz dealership in Kidlington. That proved his undoing when police were alerted to the unauthorised transactions.

Officers waited for Jordan at the car dealership and arrested him on November 11, 2005.

Jordan, of Oswestry Road, Oxford, was also found in possession of the illegal stun gun, which he said was for "self-defence".

The sentencing judge had branded Jordan a "conman, a convicted paedophile and a bigamist".

Jordan's case reached the Appeal Court today as he unsuccessfully challenged his total five-year sentence.

Mr Justice Royce, sitting with Mr Justice Lloyd Jones, said Jordan had preyed on his female victims, adding: "He is an inveterate exploiter of vulnerable women - not just financially, but emotionally".

He referred to "impact statements" from Jordan's victims which testified to the appalling emotional toll of his crimes.

Ms Turner Thomson stated that her life had been "devastated" emotionally and professionally by Jordan.

"I can't imagine that I will ever wholly recover or trust anyone again," she said.

Turning down Jordan's appeal, Mr Justice Royce ruled that five years for his string of crimes was "not a day too long".