Isobel Robertson, 38, instructed her solicitor to begin an action against Lorna Anderson, her ex-bingo partner and neighbour in Dunoon.

BBC Scotland's Forbes McFall: "The women were friends for years"

The wrangle dates back to November 1997 when Mrs Anderson won the money at Mecca Bingo in the Drumchapel area of Glasgow.

Mrs Robertson says the pair had a verbal agreement to share their winnings and is suing for �54,000 plus interest.

The women were once bingo partners

"It is regrettable that I lost my best friend as a result of this quarrel," said Mrs Robertson.

"However, I feel very strongly that I am entitled to one half of the winnings and have instructed my lawyer to go to court to prove this."

Her solicitor, Cameron Fyfe, said: "This is a very novel case.

"In Scotland you cannot sue for a gambling debt but you can sue in respect of the proceeds of a gambling dispute, which is what we have here.

"My client and Mrs Anderson had been friends for more than 12 years and regularly travelled from their homes in Dunoon to play bingo in Glasgow.

"We aim to prove that they had an agreement that if either won, then the winnings would be split equally between them."

'I feel betrayed'

Mrs Robertson added: "I feel very betrayed and very disappointed. We took her kids on holiday and I used to take her son to football.

"I know in my heart I would have paid up if I had won, and I think it is the sort of standard you have to live by.

"It is a little bit like a bereavement. You are angry, upset and emotional."

Cameron Fyfe: "Unusual case"

The computer software trainer said she met Mrs Anderson, 37, when their husbands were friends and she believed it would be difficult for them ever to speak again.

She said she could not explain why Mrs Anderson, a relief warden at a sheltered housing unit, did not pay up.

Mrs Robertson said the pair had won exactly �108,390. The �390 was paid in cash which was split on the night, but Mrs Robertson said she never saw the remainder of the winnings, despite promises she would receive varying amounts.

Mr Fyfe added: "We have lodged a writ in the Court of Session for one half of the bingo winnings. Myself and counsel are doing the case on a no-win-no-fee basis which is an indication that we think we will succeed."

Mrs Anderson declined to comment but her solicitor said she was very upset and disappointed.