The charges against Mr Berlusconi were quashed on the eve of last year's general election under a statute of limitation.

ECONOMIST: Italy, its prime minister and the law

The Supreme Court reversed his conviction under 1503, the general obstruction of justice statute, holding that the facts were insufficient to make the case.

CNN: Transcript: White House Deputy Counsel Mills' statement

As the managers stated in their presentation, there are two relevant obstruction of justice statutes: 18 USC 1503, which is the general obstruction of justice statute, and 18 USC 1512, the more specific statute which prohibits witness tampering.

CNN: Transcript: White House Deputy Counsel Mills' statement