Australia's largest casino operator, Crown Resorts, has been hit with fresh allegations that it has overseen questionable modifications to its poker machines designed to boost gambling turnover.

A former big-spending pokies player at Crown's flagship Melbourne casino has approached independent federal MP Andrew Wilkie with the allegations, and, on Tuesday, handed over detailed testimony of her experience to authorities.

The woman, whose name has not been publicly revealed, claims Crown's gaming-floor staff provided her with small plastic picks for the purpose of wedging next to the poker machines' betting buttons, holding them down, and allowing for automatic and continuous play.

She also alleges she was provided with multiple loyalty cards so she could earn loyalty points from the multiple machines she was able to play at once.