Man jailed for 'horrific' sexual assaults

A man will spend at least 15 years in jail for a horrific sexual assault that included role-play based on pornographic videos he watched before the attack.

Many details of the case heard before the County Court of Victoria are too gruesome to publish but they relate to numerous sex offences against one victim in 2015.

The man was sentenced to 19 years with a minimum non-parole period of 15 years.

Almost 20 years older than his victim, the man - who cannot be named - had no prior criminal convictions and was described as coming from a "good and decent family".

The court heard he had recently broken up with his long-term online girlfriend just before the attack that took place in his home and at another location.

It was alleged the man had planned the attack and had detailed notes relating to the ordeal.

His victim read a powerful victim impact statement to the court from behind a screen.

A series of suppression orders stop media identifying her attacker or other details heard in court.

In sentencing, Judge Lisa Hannan said the victim had "faced evil with such courage" and described the type of offending as being "every woman and parent's worst nightmare".

The court heard the accused was academically gifted and had been diagnosed with Aspergers, all of which was taken into consideration during the sentencing process.

He sat emotionless with his head bowed during sentencing, and his parents sat in court while his offending was described in great detail.

The court handed down a sentence for each offence, with the total exceeding 100 years, but many of the sentences are to be served concurrently.

He will also be placed on the serious sex offenders list and monitored for at least 15 years once he is released from prison.