The Independent Police Complaints Commission (IPCC) is appealing for information about a crash which killed a 12-year-old boy in Bradford.
Two people from Halifax have been charged over the incident on October 6 in which schoolboy Bilal Khizar died.
A 21-year-old man was charged with causing death by dangerous driving and a 21-year-old woman awas charged with perverting the course of justice.
The IPCC says it is particularly keen to speak to anyone who saw a Seat Ibiza that had been seen by police and pulled-over in a lay-by.
Bilal Khizar was hit by a car as he crossed a pedestrian crossing close to Asda supermarket in Rooley Lane. He was pronounced dead at the scene. The car also hit other vehicles.
The IPCC syas it is not investigating the death of Bilal but the events involving police before and after he was hit by a car.
A maroon Seat, registration number EF59 ULN, was first seen by police at 6.45pm at the junction of Fenby Avenue and Sticker Lane in Bradford.
Police followed it up Sticker Lane towards Dudley Hill roundabout then into Rooley Lane. The car and police travelled along Rooley Lane and on to the M606 until the Chain Bar roundabout.
IPCC Commissioner Naseem Malik said: “It is important that the events that led up to and followed this tragic incident are investigated fully and that we understand the exact nature of the contact between the police and this car. That is why the IPCC needs anyone who saw the Seat Ibiza to contact us.”
Witness can contact the IPCC ion 01924 811523 or email Lindsay.email@example.com.