TASMANIAN thieves have stolen at least $5.4 million in the past five years to feed a gambling habit.

Seventeen robbers have been convicted since 2003 for stealing money that was used to gamble, Supreme Court sentencing figures say.

The worst offender was financial adviser Mervyn William Mitchell who ripped off $4.5 million from his clients to put across blackjack tables and poker machines. The other 16 stole nearly $950,000 between them - many of them holding positions of trust.

Bureaucrat Grant David Mason had to repay more than $100,000 he stole from the Department of Primary Industries and Water in 2006 to fund the addiction he had tried unsuccessfully to kick.

And prominent Launceston businesswoman Jocelyn Sue Littlejohn stole $60,000 from the Rotary Youth Exchange to pay for her dependence on poker machines.

Many of the 17 criminals had stolen over a period of time from their employer.

Anglicare social researcher Margie Law said the figures were not surprising in light of the study her organisation had done on gambling and low-income Tasmanians.

And she says the figures are just the tip of the iceberg as they reveal only the large-scale crimes.

"We found people telling us stories about having stolen in order to finance their gambling," she said.

"Most of them were talking about small-time stuff like shoplifting."

Ms Law said the figures also highlighted the financial pressure addicts were under to fund their craving for gambling.

"There's people who lose their houses and their cars," she said.

"We have people telling us they sell their washing machines to gamble.

"They do everything they can to get as much money as they can."

She said addicts would not stop committing crimes to fund their habits until consumer protection was better.

Prime Minister Kevin Rudd criticised state Labor governments last year for hurting families with their reliance on poker-machine taxes.

A social and economic impact study of the effects of gambling, commissioned by the State Government, is due this month.

More information on the negative effects of gambling.