A TEENAGE boy was arrested last night by detectives investigating a sex attack on a mother as she walked with her two children.

The 15-year-old boy was being held in Darlington police station, where he was questioned by officers in connection with what they described as a "brutal" assault.

The attack on May 7, Bank Holiday Monday, sparked an eight-week inquiry centred on the Harrowgate Hill area of Darlington.

The assault, which took place in daylight near the railway line in Green Lane, shocked the community.

The victim, a married woman in her 30s, had stopped to put the lead on her dog, as her children cycled ahead, when the attacker pounced.

He sprang out from bushes, dragged the woman into the undergrowth and carried out the attack.

The attack was so serious that a senior detective described it as the worst he had ever encountered.

Detective Inspector Ian Phillips, of Darlington CID, said at the time: "This woman has been left mentally scarred and severely traumatised as a result of this vile attack.

"She thought she was going to die. This is one of the worst sexual assaults I have ever had to deal with."

Last night, a police spokesman said: "Following extensive police inquiries, a 15-year-old youth was arrested late this afternoon in connection with this assault.