WHY did Clare Nicholls, her brother, Simon, and her lover, Steven Martin, beat to death her boyfriend and the father of her youngest child?

Why did victim Andrew Gardner stay in the house until he died, and not seek help to stop the torture at the hands of these three monsters?

Nobody can explain why the 35-year-old didn’t simply pack his bags and leave the house of horrors that was number 14 Arthur Street.

The only possible explanation is that he loved his daughter so much, he was not prepared to leave – no matter punishment he endured.

In the end, he was physically unable to get up and go, so severely incapacitated he had become by his repeated, brutal beatings.

Experts said in the final days of his life, Mr Gardner – with 21 rib fractures and painful burns – would have been “pretty much immobile”.

Mr Gardner was a quiet, but vulnerable man – well-liked by most that knew him, and regarded as friendly and harmless.

He was described by prosecutor Paul Sloan, QC, at the end of the case as “a shy, placid, quiet individual – a man lacking in confidence”.

“He was a man who would strive to avoid confrontation and who would never fight back when confronted or stand up for himself,” Mr Sloan said.

“He was described by one particular witness as one of life’s victims, and by another as an easy target because of his timidity.”

The court heard that Mr Gardner had learning difficulties, and had been receiving counselling for depression and anxiety before his death.

Police can only assume it was the love he had for his daughter and his desire to be close to her, that made him endure months of abuse.

The cumulative effect of beatings, burnings, scalding, slashing, starving and whippings was the build up to a slow and painful death.

Over his last few days of his life, his injuries were such it was almost certain that he could not physically have left the terraced house.

Detective Chief Inspector Mick Nail, who led to complex investigation, said last night: “Many of the neighbours did not even know he lived there.

“He had become an invisible man, not allowed out because his injuries would have been obvious. He was literally tortured to death.

“Claire Nicholls had cut the pockets out of all his trousers so he couldn’t hide food and she made children take part in punishments – writing abusive words all over his body – something they thought was normal for ‘stealing’ food.

“Why didn’t he leave? Probably because he doted on his daughter. Certainly he was in no state to walk out of the house at the end.

“They let him die in the living room and after his death came up with a story that he had gone out and had returned home badly beaten.”

Paramedics doubted the story, and called police. After the battered and bruised body had been examined, they began a murder investigation.

Mr Gardner had met Nicholls when signing on at a “special needs” course on Tyneside.

She was from the Portsmouth area and had three children.

They were together for four years and during that time had a child together – a girl, who was just over a year old when he died last March.

The trial judge, the Recorder of Middlesbrough, Judge Peter Fox, described Mr Gardner’s death as “excruciatingly painful”.

Judge Fox said the three attackers had subjected him to “sadistic torture” for weeks and that they “deprived him of all human dignity”.

He, too, could only speculate about why Nicholls led her brother and Martin in the punishment beatings.

“As to your specific intention, in my judgement, it varied,”

he told her. “If it was not at any point expressly to kill, or to get rid of your lover and replace him with the next, it was close to it.”

Faces of my son’s smug killers will haunt me

forever THE distraught mother of Andrew Gardner broke her silence last night to tell reporters: “My nightmares will never go away.”

Jean Gardner was flanked by her two sons as a statement was read on their behalf by a police official outside of Teesside Crown Court.

The statement revealed her shock at his death, her pain in attending court and her anguish at seeing his killers’ “smug” faces in the dock.

Mrs Gardner and her sons, Ian, 33, and 44-year-old John, had attended almost every day of the harrowing three-week trial.

A victim impact statement given to the court told of how the death will continue to have a profound impact upon them.

Paul Sloan, QC, prosecuting, said: “Mrs Gardner is still receiving treatment and counselling and her two remaining sons have also, thus far, been unable to come to terms with what has happened.”

The statement read: “To be told that Andrew was dead was horrible and I knew there was something wrong straightaway. He was someone who would simply walk away from trouble.

“To listen to the details of how he died and the suffering he went through was beyond belief.

“The thoughts of what went on at the hands and direction of that evil woman has left me with nightmares that will probably never go away.

“Andrew was a pleasant, caring, loving lad who kept out of trouble and was never violent to anyone.

“It has hurt being here. It has hurt watching her give evidence, so much so I had to go out of the court room. I knew she was lying.

“It’s unspeakable what she and the others did. You don’t do that to another human being. They have turned our family’s lives upside down and left us empty shells.

“I called them evil to their faces in court, but it hurt even more to see their smug reaction.

“No matter how long they are behind bars, the hurt they caused will never go away. It will be with me and my family forever.”