Premier Jean Charest has asked Family Minister, Tony Tomassi to resign from his cabinet and leave the Liberal caucus after discovering that Mr. Tomassi had used a gas company credit card for his own personal purposes.
Yolande James, Minister of Immigration and Cultural Communities will take over the family portfolio.
Charest said he asked the police to investigate Tomassi's use of the credit card.
Tomassi allegedly used the card before being named a minister in December 2008.
The firing is the latest blow to the Charest government.
In the past year the Charest Liberals has faced allegation after allegation of favouritism and improprieties in Liberal Party fundraising.
Tomassi had also been under fire over reports of irregularities in awarding daycare spaces to Liberal Party donors.
Last week, he faced renewed questions from the opposition over whether his family's company, Groupe Genco, had received a contract to build or renovate publicly subsidized daycares.
Tomassi's resignation comes as as Quebec's chief electoral officer confirmed he has launched an ethics probe into his activities.
Last year allegations surfaced that construction firms had collaborated with crime families to drive up the cost of public contracts.
A special police squad, Operation Hammer, was launched to address questions of corruption and collusion in the construction industry.
Last month Charest ordered a public inquiry into Quebec's process of selecting judges after former justice minister Marc Bellemare alleged he was pressured to name certain judges to the bench based on the recommendations of major Liberal Party fundraisers.