A MORBIDLY obese rapist who threatened to kill the families of his victims if they didn't have sex with him has been jailed for eight years.

Noureldin Derwish, 27, posed as an underworld heavyweight, international drug lord, and a multi-millionaire businessman when he lured his two young victims into his evil world of lies and sick fantasies.

He also told one of his victims he knew where Osama bin Laden was living because of his significant international underworld connections.

Both of Derwish's two victims complained that they had been left crushed under his hulking 150kg frame as he repeatedly raped them.

He was found guilty by a County Court jury of 13 counts of rape, two charges of false imprisonment and three counts of making threats to kill.

The court heard today His first victim, then a 17-year-old schoolgirl, was handcuffed to a bed in a Fawkner hotel after being raped and held captive for up to seven hours.

She was then raped another three or four times.

The young girl had been waiting for her sister at Flinders St station in September 2010 when Derwish, who called himself Ali, approached her and offered her drugs in exchange for sexual favours.

She refused and gave Derwish a false name but he later contacted her on her mobile and told her she had to meet him.

He threatened that his Egyptian mafia connections would become involved if she didn't comply.

The pair met at Glenroy Station, where Derwish told her to pretend it was his birthday and that she was his girlfriend.

He took the victim to the Formule 1 Hotel in Fawkner, where he said he had a gun and told her he had people planted in the hotel he could call if she didn't do what he said.

He then raped her.

After telling her to take a shower, because it was customary to wash after sex in his culture, he raped her again.

The victim, who had grown increasingly fearful of Derwish, agreed to meet him again some days later.

He had threatened to find her family and kill them if she told police, and again reminded her of his links to the Egyptian mafia.

Derwish met his second victim, who was 23, in June 2011.

After she rejected a false job offer at one of his strip clubs, he offered her a job working for his fictitious company.

While negotiating details of the fake job, the victim repeatedly turned down requests to sleep with Derwish, including an offer of $3 million.

Derwish later told his victim that he had not wanted to sleep with her, but was testing her to see if she was a suitable candidate for the job at the company.

After the victim grew impatient with waiting to start her new job, Derwish, who went by the name Fernando, started to become aggressive.

He told her he was an international cocaine importer and threatened to kill her entire family while making her watch.

He also told the victim that his cousin was looking for a sex slave and had his eyes on her sister.

He forced the woman to have unprotected sex on a string of occasions and to make two sex videos.

Derwish shook his head as Judge Gabriele Cannon described the vile offending.

She said both victims had been left with sustained psychological injuries and were scarred by the trauma of the offences.

Judge Cannon said that while Derwish was significantly mentally impaired, the planning behind his offending showed a significant level of understanding of its seriousness.

She said Derwish, who is incontinent and had been binge eating while being held in custody because of anxiety, had suffered bullying behind bars.

They were factors, as well as his mental impairment, and the fact he would likely remain in protective custody, Judge Cannon said she considered when deciding an appropriate sentence.

He was sentenced to 12 years and three months' imprisonment and could be eligible for release after eight years.

He will be placed on the sex offenders' register for life.

Shannon.deery@news.com.au