Her solicitor, Stephen Jakobi, said last night that a similar contract - worth up to pounds 67,000 - with Columbia Pictures has also been signed by the parents and solicitor of the second heroin smuggler, Patricia Cahill, 20. They were unavailable for comment and it is not known whether Cahill has signed the deal.
The Smiths and Mr Jakobi signed the contract in May last year in the Bangkok prison where the two women were jailed.
Columbia Pictures, who reportedly view the project as a story about 'young girls overseas who run into trouble with drugs', have yet to take up the option of a film or television series.
Mr Jakobi, who will receive a percentage of any fee, said: 'They want to make a film about a campaign to right injustice. I will get the smallest percentage - the Smith's will benefit most.'
He added that publishers were currently 'queueing up' to sign a book deal for the story.