Search your conscience - that was the message delivered to an Oxford community sheltering the killers of nine-year-old Ross Doyle.

The football-mad youngster died after being knocked down by joyriders in Blackbird Leys last December.

Today, his mother Cheryl made a heartfelt plea for people to come forward with information.

Her appeal came after police offered a £10,000 reward for anyone who gives information leading to the conviction of the car driver.

Officers and the boy's family are convinced that somebody knows who is responsible - and they are desperate for the code of silence to be shattered.

At a press conference today at St Aldate's police station, Oxford, Mrs Doyle broke down and said: "There's somebody out there who knows something, Please, just come forward."

Afterwards, the 38-year-old learning support assistant, who has three other children, told the Oxford Mail: "We are overwhelmed by the police reward. We just didn't expect it. People know what is going on and they ought to take a very hard look at themselves and come forward.

"Getting a conviction would help us take the next step to normality. I cannot understand why they haven't come forward - they cannot have any conscience. The thing that cuts me is that they just left him in the street. I cannot grasp that. I feel guilty as well, there are so many what-ifs, and I am having counselling."

Ross was returning home to Redwood Close, Greater Leys, from football training with friends when he was hit by a red Vauxhall Astra, registration F581 HUR. The car had been stolen a fortnight before in the Oxford area and two people were seen fleeing.

The crash happened at 8.45pm on December 13 last year on Pegasus Road, Blackbird Leys. Since then three people have been arrested but released without charge.

Det Insp Dermot Norridge said: "We have mainly had a good response from people in the area even but there are a small group who have maintained a code of silence.

"We hope the reward will assist us in obtaining the necessary information."

Anyone who can help is urged to call, in confidence, 01865 266276 or 01865 266257.

The lines are open until 10pm on Friday and between 8am and 6pm on Saturday.