The Italian deputies walking out of Parliament at Montecitorio onto the sunny piazza outside were only too pleased to oblige when a reporter and camera crew approached and asked them for their views on the draft 2007 budget.

They posed for the cameras, offered pithy judgements on how to reduce Italy’s budget deficit, and thought nothing of it when a pretty make up girl wiped the sweat from their brows.

What they did not know was that although the cameras were real enough, the interviews were a fake - and the attentive make up girl was using drug wipes on their foreheads.

The results, according to the television programme which staged the stunt, showed that of 50 deputies "interviewed", 12 tested positive for cannabis and four for cocaine.

The sting was staged by producers of Le Iene (The Hyenas), a popular prime time show combining satire with investigative journalism.

The results, they said, showed that a third of Italy’s lawmakers had taken drugs within the previous 36 hours. The deputies thus found the results of their "interviews" all over today’s front pages - but not exactly in the way they had hoped.

Amid parliamentary uproar the show, which tonight launches its new autumn series, was ordered by Italy’s privacy authority to pull the segment on drugs and deputies.

The programme, an irreverent fast moving show aimed at younger viewers and broadcast on Italia Uno, one of the three commercial channels owned by Silvio Berlusconi, complied with the order, even though it claimed the deputies faces would have been obscured and their voices altered.

But the story was out, and the damage was done. Politicians campaigning for the liberalisation of tough anti-drugs laws passed by the former Centre Right government of Signor Berlusconi were quick to accuse their colleagues of "hypocrisy".

Paolo Ferrero, the Communist Minister for Social Solidarity, said it was "common knowledge" that "many" Italian politicians took drugs, including cocaine, adding "Perhaps that’s why the drug possession thresholds set by the last government were more permissive where cocaine was concerned compared to cannabis".

He added: "Personally I don’t appreciate this form of intrusion into people’s private lives. But the test results seem to confirm what is widely believed about drug use by many parliamentarians."

Daniele Capezzone, leader of the Radical Party, part of the Centre Left coalition, accused the privacy regulator of censorship. "I respect the regulator. But demand that the show be aired" he said. "Privacy is important, but freedom of information is even more so".

Signor Capezzone told Corriere della Sera: "I have always said that if a police dog sniffing for drugs were taken into certain political offices, first its nose would go crazy and then it would give up altogether".

Franco Grillini, a member of the ex-Communist Party of the Democratic Left - the largest government party - and a leader of the gay lobby, said he had been among those "interviewed", but had only consumed "half a bottle of Chianti, I don’t know if that counts".

Signor Grillini confessed that he had himself used drugs "in the past", adding: "I challenge Le Iene to air an interview with me without covering up my voice or face. I have nothing to hide. I’ve done drugs in the past, although now my preferred drugs are good wine and sex. Each to his own vice."

Daniela Santanche, a Far Right deputy, said that she doubted the validity of the drug wipes, and did not accept that "one in three of my parliamentary colleagues is a drug user".

Le Iene had behaved "disgustingly", she said. "Doing something like this, without the person concerned knowing, is unacceptable and a violation of the victim’s rights. I am speaking as someone who is totally against drugs".

A drugs law formulated by Gianfranco Fini, the leader of Alleanza Nazionale and former Foreign Minister, was passed in February in one of the last acts of the Berlusconi government before it lost power to Signor Prodi and the Left in April’s elections.

Adopting a "zero tolerance" approach, it made possession of both hard and soft drugs a criminal offence, with prison terms ranging from six to 20 years for dealers/

Under the legislation, those found in possession of cannabis risk having their passport and driving licence confiscated. But La Repubblica said surveys showed nearly four million Italians admitted using cannabis while 700,000 took cocaine, "and to arrive at the real figures you can at least double that".

Times Recommends

• Michael Jackson: Not the final chapter
• Indian Army spends10m rupees on golf buggies
• Brüno toned down for 15 rating