Italian former leftist guerrilla Cesare Battisti, on the run for almost four decades after escaping prison following a murder conviction, has been arrested in Bolivia and is expected to be extradited to Italy, officials said on Sunday.

"He will soon arrive in Brazil and from here will be transferred to Italy to serve a life sentence," Filipe G Martins, a senior aide on international affairs to Brazilian President Jair Bolsonaro, tweeted.

Italian Interior Minister Matteo Salvini, who is also deputy prime minister, told Italian television he hoped Battisti - who lived in Brazil for years - would be back in Italy by the middle of the week.

Brazilian National Security Adviser Augusto Heleno told reporters after a meeting with Bolsonaro that Brazil had sent a plane to Bolivia to bring Battisti back. Italy said it had dispatched a plane carrying Italian police and intelligence officers to South America to collect Battisti.

Heleno said that in principle Battisti would come to Brazil first, but that "nothing has been decided exactly."

Battisti, 64, faces life in prison in his home country, where he was convicted of four murders in the 1970s as a member of the far-left Armed Proletarians for Communism. He has denied responsibility for any deaths.

He escaped from prison in 1981 and lived in France before fleeing to Brazil to avoid extradition. Battisti, who has a five-year-old Brazilian son, lived in Brazil with the support of former left-wing President Luiz Inacio Lula da Silva.

However, the far-right Bolsonaro, who took office this month, pledged to return Battisti to Italy. In December a Brazilian Supreme Court judge ordered Battisti's arrest but by then he had already vanished again.

Salvini said in a statement: "I thank with all my heart the president Jair Bolsonaro and the new Brazilian government for the changed political climate."

Salvini, head of the right-wing League party which partners the 5-Star Movement in Italy's ruling coalition, was one of the first top European politicians to endorse Bolsonaro's election.

Italian President Sergio Mattarella expressed on Sunday his satisfaction at Battisti's arrest. "We hope Battisti is swiftly handed over to Italian justice," he said.

Battisti, who became a successful crime novel writer, said last year he would face torture and death were he to be sent back to Italy.

His lawyer told Reuters last month that he had filed an appeal against the Brazilian Supreme Court decision, seeking to block another attempt to extradite his client.