Finance minister and leader of the Militant Socialist Movement (MSM), Pravind Jugnauth, said his colleague Santi Bai Hanoomanjee was innocent of charges that she had inflated a government tender to acquire a private hospital.
The health minister, who was arrested last week, was one of the six who resigned.
“We have decided to resign from cabinet to show our solidarity with our colleague, the minister of health, who, according to us, is innocent,” Jugnauth told a news conference.
Jugnauth said his party would remain in the ruling alliance with the Labour Party.
He was appointed finance minister after a parliamentary election in May 2010, in which MSM and the ruling Labour Party ran as an alliance. It won 41 out of 62 seats, handing Prime Minister Navinchandra Ramgoolam a second term.
Ramgoolam is in London. He told local newspaper Le Mauricien on Tuesday that Jugnauth had informed him of the decision to resign on Tuesday morning. He said he would be returning to the Indian Ocean island at the weekend.