Police have arrested six people accused of taking part in a tax-cheating scheme by two Tuscan construction companies that was allegedly devised by a mobster.

Tax police Lt. Col. Antonino Raimondo said Wednesday the Uffizi Gallery in Florence was among the places where the companies had done construction work.

Raimondo said in a telephone interview that a convicted Camorra boss masterminded the scheme, in which fake receipts for nonexistent construction expenses were used to save the unidentified companies 3.1 million euros in taxes.

He said the illicit savings gave the companies an unfair advantage in bidding for legitimate contracts, including a subcontract for work at the Uffizi, which wasn't aware of the mob links.

Raimondo said mobsters took 4 percent of the income for the "expertly done" construction.