Brazil's Supreme Court has ruled against extraditing an Italian fugitive wanted for four murders dating from the 1970s, a decision that could raise tensions between Brazil and Italy.

The court Wednesday said the former left-wing militant, Cesare Battisti, can remain in Brazil. The top court's ruling upholds last year's decision by then-President Luiz Inacio Lula da Silva to deny the extradition.

Battisti, who once belonged to an armed communist movement, faces possible life in prison if extradited to Italy.

He has been on the run since the 1980s, when he escaped from an Italian prison while awaiting trial. He was convicted in absentia of two of the murders, and was re-arrested in 2007 in Brazil.

In 2009, Brazilian authorities angered Italy when they granted Battisti political asylum, saying he risked persecution if extradited. Battisti has always maintained his innocence.