An Italian policeman accused of raping an Australian teenager he met through the Couchsurfing website spiked her drink with tranquillisers, prosecutors say.

Dino Maglio, 35, is suspected of carrying out or attempting similar assaults on up to 15 other women he met through the popular travel site.

On the opening day of a trial which has reignited safety concerns surrounding the website, the prosecution said he should go to jail for seven years and four months for the alleged assault on the Australian minor.

• Vanuatu food shortage fears
• Carnarvon wonders if it will ever recover

As most of the facts of the case are uncontested, it is being dealt with under closed-door, fast-track procedures which mean a verdict could be announced at the end of the next one-day hearing, which was scheduled for April 18.

Lawyers representing the interests of the victim requested damages of 250,000 ($A345,853) for her and a further 50,000 euros ($A69,170) for the trauma suffered by her mother, who also stayed at Maglio’s apartment in Padua, near Venice, on the night of the March 2014 attack.

The Italian Ministry of Defence, which is Maglio’s employer, is seeking damages of 936,000 euros – one for every citizen in the province of Padua.

Maglio is charged with raping a minor with the aggravating circumstance of having administered a narcotic without her knowledge.

According to the prosecution’s account, the girl, who had stayed up chatting to Maglio after her mother and younger sister had gone to bed, was given a drink he had spiked with tranquillisers, a type which have featured regularly in date-rape cases.

When the mother woke in the morning, she discovered her daughter in Maglio’s bed without her underwear and in a state of extreme lethargy.

• St Patrick’s Day message causes offence
• Hockey seeking ‘substantial damages’

Arrested after the family filed charges in Venice, Maglio admitted having spiked the girl’s drink and to having sexual intercourse with her while she was under the influence but claimed the sex had been consensual.

Police confiscated a stock of 40 Tavor pills at his apartment. Tavor is the Italian brand name for Lorazepam, a powerful anti-anxiety drug.

Couchsurfing is a social networking site that puts travellers in touch with hosts who are willing to put them up and show them around their hometowns for free.

The site’s declared aim is “a world made better by travel and travel made richer by connection”. But its model has been criticised because of previous incidents of travellers being attacked by hosts they know nothing about.

Maglio is expected to face further cases once prosecutors complete their examination of statements made by 15 other women who say they were drugged sexually assaulted or both by the policeman, who used the fake name “Leonardo” to present himself as an amiable and generous host.

The women include nationals of Canada, the Czech Republic, Germany, Hong Kong, Poland, Portugal and the United States.