Alison Twiss became a blackmail victim after she had already loaned him about £13,000 worth of her own money to help him out, Liverpool Crown Court heard.

Her dishonesty came to light when no payments were made on the nine loans she had authorised from the Halifax for Fawzi Abuarghub and his friends. Abuarghub himself hit the headlines after fleeing to his homeland of Libya with his daughter Nadia and is wanted for abduction.

Twiss, a 33-year-old mother-of-two, has lost her marriage and job as a result of the incidents and was now likely to lose her home, said William Swalwell, defending. "She did not receive the benefit of these crimes but will have to foot the bill. Looking back she cannot believe how stupid and naive she was," he said.

She had formed a relationship with Abuarghub and he began borrowing money from her and the sums became larger and larger. Her family found out and she promised to end the affair and get the money back.

But he then asked her to authorise a £7,000 loan and when she refused he threatened to show her family the sex video of them. He then got her to authorise more loans for him and his friends, said Mr Swalwell.

Jailing her for 12 months, Judge John Roberts said: "At the end of the day you did not benefit by one single penny but that in no way lessens the amount lost by the bank."

He told blonde-haired Twiss that he took into account her previous good character and the fact that it had been two years from first being questioned by police until she was charged.

Twiss, of Calton Close, Highfield, pleaded guilty to nine offences of obtaining money transfers, totalling £83,400 by deception between November 2004 and January 7, 2005.

Mr Harry Pepper, prosecuting, said that she had been employed by the Halifax in Wigan for 13 years. Her role as a bank adviser included authorising loans.

An internal investigation revealed she had authorised loans to Abuarghub and others at an address in Bolton for which no repayments were made. When interviewed she confessed.

She told police how Abuarghub had threatened to show the video on his mobile phone of them having sex and pressurised her to authorise loans. She was not charged until last year while investigations continued into Abuarghub.