A FATHER'S 26-year campaign for justice took a major step forward yesterday after a paedophile who tried to kill his son was jailed for ten years.

John Sykes – regarded as one of the country's most dangerous child sex offenders – admitted a catalogue of crimes against a young boy decades ago.

The 53-year-old has been described as a dangerous sexual predator who claimed to have abused up to 80 young boys when he lived in West Yorkshire.

But when he lived on Teesside, the monster abused a boy before smashing his head in with a house brick to stop him ever telling the police what had happened.

He later told another young sex abuse victim, aged 14: "I had to kill the little b*****d. I don’t know how he survived. I went to town with him.”

However, the eight-year-old did survive the July 1991 attack, but Sykes was prosecuted only for causing grievous bodily harm, and received just four years.

The victim's father is taking legal action against Cleveland Police claiming the force allegedly hid evidence at the time – believing it was because of his notorious reputation.

He admits he grew up on the "wrong side of the law" and dislikes the police, but says that should not have stopped them properly investigating the attack.

Cleveland Police last night confirmed they are examining the father's complaints, and said "there may now be further information to consider".

Sykes is already serving an indefinite sentence of imprisonment for public protection, and might now be behind bars for the rest of his life.

He denied a charge of attempted murder against the boy in 1995, but admitted GBH – which was accepted by prosecutors – and got four years for it.

He was jailed indefinitely, with a minimum of 42 months, in Leeds in 2010 for sexual activity with a child and breaching a sexual offences prevention order.

Last night, Assistant Chief Constable Jason Harwin from Cleveland Police, said: “Over time we have received a number of highly complex complaints and allegations of a historic nature from a family member of the victim.

"The complaints span a twenty year period and have been investigated; however we are aware that there may now be further information to consider. As the trial has now concluded, we will be reviewing the complaints that have been made.”

The victim's father said: “This conviction has opened up many years of hell for me.

“I’ve suffered from post traumatic stress disorder after finding my boy left for dead.

“It has caused me to lose friends and family as I isolated myself.

“This has been a long road for me. I hope this is the beginning of the end so I can get on with my life.”