INVESTIGATORS believe toxicology tests may hold the key to finding out why a man died after being taken into police custody.

An inquiry by the Independent Police Complaints Commission was launched at the weekend following the death of Nadeem Khan, from Blackburn, who was arrested in Brierfield.

Police said he was taken into custody after a "violent struggle" with officers in the Halifax Road area.

A post mortem examination on Mr Khan, 28, could not establish a cause of death, but IPCC commissioner John Crawley said it had "answered certain crucial questions".

Mr Crawley said it found that Mr Khan showed no signs of serious trauma injuries or natural disease.

He said that Mr Khan had bruises and abrasions consistent with witness and police accounts of how he had broken windows and showed violence, before violently resisting' arrest when the police attended.

Now it was thought toxicology tests may hold the key, Mr Crawley said.

Mr Crawley said: "The IPCC is making good progress with its independent investigation of the incident.

"The results of toxicology tests, which may take some weeks to complete, may enable the pathologist to reach a firm conclusion on the cause of death for the benefit of the inquest.

"In the meantime I have agreed fast-track inquiries we aim to complete over the next week.

"These will enable us to establish that the police handling of this incident met appropriate standards, thus providing appropriate reassurance for Mr Khan's family and the local community that a rigorous independent investigation has been undertaken.".

Mr Crawley said the IPCC's inquiry should be complete within a week.

He said: "Lancashire Constabulary will then complete a report for the coroner's inquest.

"If however our investigation raises any significant concerns to be resolved, including any significant questions Mr Khan's family wish to have an answer to, we will extend our own independent investigation.

"We will in any event be offering to meet Mr Khan's relatives to provide a full explanation of our findings.

"This has been a stressful time for all those involved in this incident.

"It is always a shock when someone as young as Mr Khan dies so suddenly, and my thoughts are with Mr Khan's family."

While awaiting the toxicology results, the IPCC will be reviewing CCTV footage, police records of the incident, getting further witness statements, and looking at handling of how Mr Khan was taken to hospital Mr Khan was arrested at 8.50am and was taken ill a short time later at the police station.

He was taken to hospital were he was pronounced dead at 10.30am.