FILE PHOTO: Giuseppe Salvatore Riina (L), the son of the most feared Sicilian Mafia boss, leaves a prison in Sulmona, central Italy, in a February 28, 2008 file photo. REUTERS/Claudio Lattanzio/Files

ROME (Reuters) - An Italian judge ruled on Tuesday that a convicted mobster and son of late boss Salvatore “Toto” Riina be detained for a year in a secure labor unit, a judicial source said, less than two weeks after his father died, leaving the Sicilian mafia’s future uncertain.

Convicted of mafia membership in 2004 and sentenced to nearly nine years in prison before being released on parole, Giuseppe Salvatore Riina, 40, has been under police surveillance in the northern town of Padua.

Criminals who are deemed dangerous to society or likely to re-offend can be sent to a secure unit, known as a “workhouse” in Italy, with the aim of rehabilitating them into society through manual labor.

In Riina’s case, investigators in Rome found that he had contact with drug dealers, prompting a prosecutor in Padua to ask for him to be held under tighter security, the source said.

Riina declined to comment through his lawyer.

A decision has not yet been taken on which of Italy’s five workhouses Riina will be sent to, the source said. The judge handed down a one-year term, rather than the three years the Padua prosecutor had requested.

On state television last year, Riina said he had been happy during his childhood, when his fugitive father lived under an assumed name.

Toto Riina died on Nov. 17 in a hospital in Parma, the Italian city where he had been serving 26 life sentences for murders committed between 1969 and 1992.

Nicknamed the “boss of bosses”, Toto Riina changed the structure of the Sicilian mafia, concentrating power in his own hands. His savagery prompted hundreds of mobsters to testify against him, allowing magistrates to uncover the secrets of Cosa Nostra and prosecute its leaders.