The woman whose evidence helped put serial fraudster John Keady behind bars has spoken of how she has spent two years fighting to be "the nail in his coffin".

Mabel Arnill, from Saltash, lost around £15,000 when her six-week relationship with Keady turned sour.

But the defiant 34-year-old was one of a few of the conman's victims courageous enough to stand up and battle for justice.

After seeing Keady jailed, she said: "I suspect there are an awful lot of victims out there who haven't come forward. But he pushed it too far with me – I'm the mistake he made."

Watersports enthusiast Mabel, a manager for Plymouth City Council, met Dr John 'Taz' Keady through the Tamar Canoe Association in December 2007.

He told her he was a successful businessman and with his Gucci clothing and £3,000 watch, Mabel had no reason to suspect he was actually an unemployed con-artist using a fake name.

The pair immediately struck up a friendship, kayaking and walking their dogs together, Keady even offering Mabel a job with his business.

In the lead-up to Christmas he told Mabel he was bidding for the 'perfect' kayak as a gift on auction website eBay.

When she refused to accept it she handed over her credit card details so Keady could pay the £350 on her behalf.

The kayak never arrived, but was later found in his mother's garage in Callington – apparently placed online as a ploy to access Mabel's credit card.

Then, on Christmas Eve, Keady pulled off one of his most audacious scams.

Having claimed to have lost his wallet – and therefore unable to access the millions in his offshore accounts – he received a fictitious phone call from a "friend who was stranded in the Himalayas".

Mabel lent him £1,000 that week to help launch an £11,000 "rescue mission".

"It was all so believable," she said. "He appeared to be having real phone conversations.

"Now I realise that right from the minute he decided he was going to lose his bank cards I became a pawn in his game.

"It was all calculated and what makes it worse is that he actually targeted me – he picked me out and thought, 'She fits the bill'."

"He's just a complete scumbag," she said. "He is more convincing with lies than anyone can be with the truth."