A foul-mouthed Silvio Berlusconi is caught saying he wants to leave Italy, according to a leaked phone conversation published by Italian media as part of a probe into a blackmail plot against the prime minister.

"I'm so transparent, so clean in everything I do. There's nothing I could be reproached for. I don't do anything that could be seen as a crime. People can say I f*** but that's all they can say," Berlusconi was quoted as saying.

"I couldn't give a f***. In a few months I'm going to go away and mind my own f****** business. I'm leaving this s*** country that makes me feel like puking," he said, according to the report by Italian news agency ANSA.

The report said the conversation occurred on July 13 between Berlusconi and online newspaper editor Valter Lavitola, who is wanted in the context of an inquiry for blackmail against Berlusconi that led to two arrests on Thursday.

Lavitola is accused of being the intermediary in blackmail payments from Berlusconi to Giampaolo Tarantini, a businessman who said he paid women to attend some raunchy parties hosted by the prime minister and have sex with him.

Tarantini and his wife Angela Devenuto were arrested earlier on Thursday.

Police "have arrested Giampaolo Tarantini, 34, and his wife Angela Devenuto, 32, for extorting Prime Minister Silvio Berlusconi", a police statement said.

Tarantini in 2009 claimed to have paid around 30 women including a prostitute, Patrizia D'Addario, to entertain the prime minister at his homes.

He had said the women attended 18 of Berlusconi's parties in Rome and Sardinia in 2009 and 2010 and provided sexual favours "if the need arose".

Tarantini, who works in the medical industry, is a suspect in several investigations for corruption and has already been convicted.

According to prosecutors quoted by Panorama, a magazine owned by Berlusconi's family, Tarantini extorted monthly sums in exchange for telling investigators that Berlusconi did not know the women were paid.

The money, including an initial payment of 500,000 euros (700,000), was also intended to persuade Tarantini to opt for a fast-track trial in order to avoid a lengthier process that could have brought to light "embarrassing" details.

"I presented them as my friends and I did not mention the fact that sometimes I paid them," Tarantini said in one of his earlier interviews.

Having sex with prostitutes is not a crime in Italy but Berlusconi likes to defend a macho image and insists he has never had to pay for sex.

In a book about her two nights with Berlusconi in 2009, D'Addario said: "Berlusconi knew I was an escort. And I wasn't the only one."