Battisti was detained late Saturday in Bolivia "and will be soon brought to Brazil, from where he will probably be sent to Italy to serve a life sentence," tweeted Filipe G. Martins, a senior aide on international affairs to Brazilian President Jair Bolsonaro.

Italy has repeatedly sought the extradition of Battisti, who has lived in Brazil for years under the protection of former leftist president Luiz Inacio Lula da Silva, now in prison for corruption.

During Brazil's recent presidential campaign, the far-right Bolsonaro -- who took office on January 1 -- vowed that if elected he would "immediately" extradite Battisti.

In mid-December Brazil's outgoing president, Michel Temer, signed an extradition order for Battisti after a judge ordered his arrest. By then the Italian ex-militant was nowhere to be found.

Battisti was arrested in the Bolivian city of Santa Cruz de la Sierra, Brazilian Federal Police sources told Brazilian media.

Battisti escaped from an Italian prison after being convicted in 1979 of belonging to an outlawed leftist group, the Armed Proletarians for Communism.

He was subsequently convicted in absentia of having killed two members of Italy's police forces, taking part in the murder of a butcher, and helping plan the slaying of a jeweler who died in a shootout which left his 14-year-old son in a wheelchair.

Battisti admitted to being part of the group but denied responsibility for any deaths.

He reinvented himself as an author and in 2004 skipped bail in France, where he had taken refuge. He went to live clandestinely in Brazil until he was arrested in 2007 in Rio de Janeiro.

After four years in custody, then-president Lula issued his decree -- later upheld by Brazil's Supreme Court -- refusing Battisti's extradition to Italy, and he was freed, angering Italy.

Battisti, who has a five-year-old Brazilian son, last year told AFP he faced "torture" and death if he were ever to be sent back to Italy.