**WARNING: This article contains some graphic content.

A man who brutally beat and raped three young women over a 20-year period – including imprisoning one victim in a cell made of hay bales – has been sentenced to preventive detention.

Nathaniel Ejay Pikitea Webster, 43, was sentenced in the High Court in Tauranga on Friday by Justice Christian Whata.

He had earlier been found guilty by a jury of 28 charges of sexual and physical violence, many of which were representative, meaning they covered multiple offences.

He also pleaded guilty to two representative charges of male assaults female.

Many of the details of Webster's offending, including the locations it happened, cannot be reported without revealing the identity of his three victims, each of whom were left severely traumatised by his actions.

He met his first victim in 1996 or 1997, when she was about 16 years old. While he was initially kind to the teenager, it was not long before the relationship became abusive and sexually violent. Over the following years he raped and violated her numerous times.

On one occasion he invited her to a party, but took her to a nearby field of maize where, 'treating her like a rag doll”, he brutally raped her.

In another incident, Webster abducted the girl from her own bedroom, put her in the back of his car and drove her to a barn where he had built a cell made out of hay bales, from which she was unable to escape.

Over the following few days, he returned several times and raped her on multiple occasions.

She only managed to escape because her cries were heard by a farmhand who helped her out.

As the judge pointed out during sentencing, 'at one stage you were interrupted by your father, but that did not deter you”.

Webster's offending against his second victim, who was 16 when they met, happened over a 10-year period between 1997 and 2007. Over that time he raped and sexually violated her many times.

He also frequently physically assaulted and injured her. As Justice Whata noted during sentencing, she 'gave evidence that she could not even remember how many ‘hidings' she received … she was kicked, smacked and punched in the head and other parts of her body, sometimes unable to walk”.

On one occasion, Webster tied a belt around her neck and dragged her around the house. In another incident, he put her in a sleeper hold until she was knocked out.

She was pregnant at the time.

The third victim, again, was 16 when she met Webster, and was likewise subjected to numerous rapes and beatings, including slamming her head into a truck window on one occasion.

All three victims said their lives had been irrevocably changed by Webster's violence towards them. They had suffered nightmares and panic attacks, feelings of low self-worth and had turned to alcohol and drugs to cope.

As the court was told, Webster's father was a patched gang member who lived a life of heavy drinking and parties and used 'hidings” as a means of disciplining his son. Webster himself joined the Mongrel Mob when he was 15.

As the judge noted, 'You saw your father kick people's heads in and uncles smash-up people. You remember witnessing your uncle viciously beating an aunty until she was unrecognisable, hitting her like she was a man.”

Justice Whata had the benefit of two psychological reports for Webster, one of which found his offending appeared to be 'driven by deviant sexual fantasies”.

He was also observed to be 'emotionally shallow, such that you avoid close and affectionate relationships, enabling you to perform cruel and instrumentally violent sexual acts”.

The other report had concluded Webster had 'a demonstrable capacity for vengeance and sadistic cruelty and use all types of aggression instrumentally”.

Due to his lack of remorse and personal responsibility, his egocentric outlook and other factors, Webster was assessed to be of very high risk of committing further sexual violence and unlikely to engage and benefit from treatment.

Justice Whata sentenced Webster to 18 years and 10 months for the lead sexual violation offending. However even that lengthy sentence was not enough.

'The combination of the pattern of your offending, your trenchant denial of it, the very high risk of offending posed by you, mean that I consider preventive detention is necessary to protect the public from you.

'Your clear tendency to manipulate and then to grossly abuse your victims is not something I can be satisfied will be addressed over time.”

-Stuff/Mike Mather.