In the spring of 2017, Andy Anokye – also known as the grime artist Solo 45 – felt on top of the world. He had signed a deal with a world-famous record company, was headlining major festivals in front of tens of thousands of adoring fans, and enjoying the trappings that fame was bringing: money, freebies, privilege and champagne-soaked after-show parties.

In reflective moments, he would watch crews rowing on the River Avon outside his waterside apartment in Bristol and think about his journey from a deprived estate in north London, where he rubbed shoulders with gangsters and crooks.

But Anokye was hiding a secret. He used his position of power – and his charisma – to meet and groom women. He would charm them and win their trust before subjecting them to horrific campaigns of rape and abuse.

The videos he made of his crimes were so obscene, extreme and intimate that the trial judge at Bristol crown court, William Hart, cleared the public gallery when they were shown and, unusually, allowed only two members of the media to view them.

Four victims bravely gave evidence against Anokye despite their fear of the star and knowing that they would be questioned in detail.

Anokye was found guilty on Wednesday at Bristol crown court of 30 charges relating to a two-year period. He was unanimously convicted of 21 rapes, five counts of false imprisonment, two counts of assault by penetration and two of assault occasioning actual bodily harm.

His victims described how he systematically terrorised and sexually abused them. He tied them up, beat them and imprisoned them. He waterboarded some of his victims and hit or threatened them with weapons including a handgun.

One described her terror at being waterboarded. “He put me on the bed and put a flannel over my face and poured a bottle of water over it, which made made feel like I was drowning.”

He stabbed one woman in the thigh, leaving her needing hospital treatment, and held the blade to her throat and on another occasion. He routinely hit her face and beat her around the body.

“I had swelling for about six months after,” she said. “My eyes were red, swollen … around my eyes was black. I went out once in this time, and wore sunglasses and didn’t look at anyone. I had bruising under my left and right arms, and right down my chest under my breasts. It was like I had a black T-shirt on.

“When he wasn’t getting any more fun out of hitting me, because I wasn’t fighting it any more, he then started to threaten my family.”

He drove one woman to an isolated spot and told her to remove jewellery that could identify her, claiming there were people hidden in the woods ready to shoot her.

Anokye derived sexual pleasure from inflicting pain and suffering on his victims. He sent a text message to one, saying he wanted to “see the fear in your face”. A man of words, he looked up the word for his fascination – “dacryphilia” is the term for sexual arousal from another’s fear.

In the witness box Anokye freely said he liked to slap, choke, bite and grab women by the hair. He admitted that he would sometimes throw women around and tie them up with rope or handcuff them and verbally abuse them during sex. Anokye said the women would be left sometimes with bruises, “raised skin”, sore throats or carpet burns.

He also told the jury he liked to interrogate the women about their previous partners and, from his late teens, had habitually filmed sexual encounters and watched the videos back.

Anokye insisted that the women had consented. “I don’t think women I was involved in would look at me and think: ‘He’s going to make slow, sensual, candlelit love to me.’ They knew the sex I was into. I would tell them it would sometimes involved terrorising. We would do a lot of things where I would push the boundaries.”

He insisted he would not have risked what he had achieved by raping women. “At that time in my life, things were going so smoothly,” he said. “Everything was working so well. I would never do anything to put my freedom on the line … life was too sweet.” He also said he didn’t have the time to imprison anyone as he was too busy.

But he slipped up. Asked in the witness box whether he ever continued sex when a woman had said she wanted him to halt, Anokye initially said he “usually” stopped, but swiftly corrected himself to “always”.

Anokye rose from tough beginnings on the Broadwater Farm estate in Tottenham, north London, where he was brought up by his mother. For him it was a dangerous place, where gangs, guns and police chases were common. As a teenager, he was convicted of beating up a younger girlfriend and found guilty of threatening someone with an airgun in a barber’s shop. He was the victim of a stabbing.

Anokye got into music when he was in his mid-teens and started performing at small venues. He became involved in the pirate music scene, meeting other members of the grime collective Boy Better Know and coming up with the name Solo 45.

The jury was shown a video of Anokye performing with Boy Better Know in front of thousands at Earls Court in 2014 – a show that changed his life. In 2016 Boy Better Know went on to star at Reading and Leeds and the Wireless festival in London.

Anokye signed with Island Records. He told the jury it was an emotional moment – he had gone from a life among gangs and drugs to being able to afford that riverside flat in Bristol and a villa in the Mediterranean.

He was caught after abusing another woman. She described how he spat on her during the abuse and put a flannel with cleaning fluid over her face. Anokye threatened to “bury her” if she went to police, but in April 2017 she did just that.

It led to the discovery of thousands of videos on his phones and devices, many of them showing women being grievously abused. Other women were traced and spoken to. Anokye was arrested and has remained behind bars since.