Battisti became a successful crime writer after moving to France
Italy has summoned Brazil's ambassador to protest against his country's decision to grant refugee status to a former Italian left-wing radical.
Cesare Battisti, a former member of the Armed Proletarians for Communism, is wanted by Italy in connection with the murders of four people.
He escaped from an Italian prison in 1981, while awaiting trial, and went on to reinvent himself as a novelist.
He has repeatedly denied any involvement in the killings.
Mr Battisti was convicted in absentia by an Italian court and sentenced to life in prison in 1990 for the murders of a prison guard and a butcher in the 1970s.
He is also accused of being an accomplice in two other murders, including the killing of a police officer.
The former radical has always denied involvement in the killings, and in his memoir published in 2006, he protested his innocence.
"I am guilty... of having participated in an armed group with a subversive aim and of having carried weapons, but I never shot anyone," he wrote in "Ma Cavale" or "My Escape".
Brazil's decision to grant Cesare Battisti asylum has provoked outrage in Italy.
The Italian foreign ministry summoned the Brazilian ambassador to Rome to convey Italy's "unanimous outrage".
The Italian Association of Victims of Terrorism said the release of Mr Battisti was unacceptable.
"[It is a] further wound to the Italian people, the victims and their relatives who have been subjected to the blind and bloody violence of terror," it said in a statement.
Brazil has defended its decision.
Brazilian Justice Minister Tarso Genro said he believed Mr Battisti risked persecution if extradited to Italy.
"I am absolutely convinced that we have taken a correct position," he told reporters in Sao Paulo.
Mr Battisti was first granted asylum in France in 1990 by then President Francois Mitterrand after he agreed to renounce violence in return for sanctuary.
But he fled to Brazil in 2004, after France reversed its decision and agreed to extradite him to Italy.
He was arrested in 2007 in Rio de Janeiro in a joint operation by Italian, French and Brazilian police.
Camilo Toscano, a spokeswoman for Mr Battisti's lawyer, said the Supreme Court might grant Mr Battisti's release as early as Thursday.