Mining companies are yet to deposit a single dollar into a regional infrastructure fund set up in exchange for a freeze on coal royalties.

In May last year, Treasurer Jackie Trad promised coal royalties would not be increased for three more years “in exchange” for millions of dollars in contributions from mining giants to a regional infrastructure fund.

Mining companies are yet to contribute to Jackie Trad's "voluntary" infastructure fund. Credit:Darren England

“So, a three-year freeze on any changes to Queensland's royalty regime, but I want these companies to think about making an additional contribution through this fund to the regional communities in which they operate," Ms Trad said last year.

The government funnelled $30 million to kick-start the fund and hoped miners would chip in $70 million to bring the fund to $100 million.