Five men, who worked in a mechanic's shop at the MDOT office in Yazoo City, were indicted by a grand jury earlier this month and arrested Tuesday.
State Auditor Stacey Pickering said two more were arrested Wednesday.
In the latest arrests, Joseph C. Gallagher, an MDOT employee, and Ricky Saxton are accused of fraudulently obtaining public funds and conspiracy to fraudulently obtain public funds.
It wasn't immediately clear if they had lawyers.
Saxton owns and operates Ricky Saxton's Repair Shop in Yazoo City. Officials say Saxton knowingly fulfilled orders placed by MDOT maintenance employees for use on vehicles owned by a private party.