A disgruntled gambler with a TV game show obsession is believed to be behind the extortion attempt that forced Mars and Snickers bars off the market in New South Wals, according to the Sunday Telegraph newspaper.

The Sunday Telegraph has learned the extortionist holds a grudge against the Star City casino and hints in his letters that he believes he is owed a fortune, the paper said.

Sources close to the investigation say he feels “hard done by” that he is not a rich man.

But while money appears to be the issue, the extortionist’s precise demands are unclear in the rambling letters delivered to the casino and to MasterFoods, the snack bar manufacturer caught up in the blackmail attempt.

The bizarre notes refer repeatedly to a popular TV game show that has no apparent connection with the casino or the food company.

Detective Superintendent Peter Cotter, who is in charge of Strike Force Caliban investigating the extortion attempt, said the game reference was a “key part of the investigation”. But he said the exact motive was a mystery.

Police are no closer to determining why MasterFoods was chosen to put pressure on Star City, which police identified as the prime target of the extortion attempt.

A contaminated Snickers bar was sent to MasterFoods on June 8, accompanied by the first of five letters.

The food company withdrew its top-selling Mars and Snickers lines from sale on 1 July when it received threats seven poisoned chocolate bars had been placed in Sydney stores.

Star City chief operating officer Jim L’Estrange said he had a lot of sympathy for MasterFoods’ position.

“They have had to make some tough decisions and we respect them for the way they have done that,” he said. But there had been no talk of compensation between the companies.

MasterFoods president Andy Weston-Webb said he hoped the public would continue to have faith in the food company.

“We have a very trusting relationship with the community and I hope we’ve honoured that in the way in which we’ve responded to this,” he said.