The prosecutors also asked the court in Milan for prison terms of eight to 10 years each for Leone's three accomplices, all charged with holding Giuseppe Spinelli, 71, and his wife Anna hostage in their home for 11 hours and forcing them to call Berlusconi to try to get 35 million euros (about $46 million) in ransom last October, ANSA reported.
The abduction and extortion attempt were not reported until the day after the Spinellis were released, prompting speculation in the Italian media that ransom was paid.
Defense attorneys denied the speculation and prosecutors said they had no evidence to support such a claim, ANSA said.
Berlusconi is on trial in Milan for allegedly paying for sex with an under-age prostitute at sex parties at his home. Investigators in Berlusconi's trial said Spinelli was tasked to give cash gifts to women who took part in the parties.