A 12-year-old boy was left 'distressed and traumatised' after being brutally raped in Darwen, detectives said.

And a 44-year-old man was tonight being quizzed on suspicion of rape.

Police said they made the arrest after spotting a suspect on CCTV footage from the surrounding area.

The boy had been playing in the Sudellside area about 8.30pm yesterday when police said he was approached by a man who offered him cash to help look for a lost dog.

The pair are said to have then walked to Marsh House Lane and into the woods, known locally as Bailie's Field.

He was subjected to a lengthy and violent assault before he was let go, officers said.

The boy was able to make his way back to the main road and get help from a passing motorist. Police were called to the scene at 10.35pm.

Det Supt Mick Gradwell, senior investigating officer, said: "The boy was subjected to a very brutal, vicious and violent sex attack.

"It was an horrendous attack that has gone on for some time."

An incident room was set up and 60 officers were briefed on the case yesterday morning in order to start the hunt for the attacker.

Officers swooped on an address in Darwen town centre less than two hours later and a man was taken into custody at about 11am.

Det Supt Gradwell said: "As a result of an inquiry looking at CCTV footage from the area a man has been arrested and will be questioned by police."

He added: "This is a very serious investigation and we have followed numerous lines of inquiry, including house to house calls, checking CCTV footage and the collection of forensic evidence."

The 12-year-old has been interviewed by officers who are specially trained to deal with young victims and witnesses.

"The boy is very distressed and traumatised by what has happened," said Det Supt Gradwell.

"His family are also in shock. We have a family liaison officer with them and are doing everything we can to help them.

"This was a 12-year-old boy who was just going about his business and he has been subjected to an awful attack.

"It is very concerning when something like this happens but I would like to point out this incidents like this are very rare. But even one is one too many."

A large area of the wood was cordoned off while forensic experts combed the area for evidence.

Police are appealing for anyone with information to contact them.

Det Supt Gradwell said: "I am making a plea to anyone in that area who may have seen a man and a boy together, or to anyone else who may have been approached by a man seeking assistance in finding a dog, to come forward with information.

"It is very important that people respond to this appeal."

Call police on 01254 51212 or Crimestop-pers on 0800 555 111.