John and Doug Streeter had been hit several times by gunshots, The (Ballarat) Courier reported. Doug Streeter's wife discovered their bodies at about 6 p.m. Thursday on their farm at Natte Yallock near Avoca in Victoria.
Police were investigating a wallet found at a recycling plant in Bendigo, more than 50 miles away, The Bendigo Advertiser said. No information was released on its possible connection to the crime.
The newspaper said police officers closed the plant at about 3 p.m. Friday, sending employees home.
The Streeter farm is an isolated property at the end of a dead-end road more than 2 miles from the hamlet of Natte Yallock.
Friends described the brothers as "utter gentlemen" and said the small community is in shock about the killings.