The family of a man who died in police custody have criticised a fresh IPCC review into his death.

Sean Rigg, 40, of Tooting, died in Brixton police station in 2008 after he was arrested in Weir Road, Balham.

An inquest jury returned a damning narrative verdict last month, finding there was an "unsuitable" level of force used when officers arrested him.

A report published by the Independent Police Complaints Commission (IPCC) today said officers did not recognise Mr Rigg as a man with mental health problems.

But it found a three hour delay in responding to emergency 999 calls was not unusual, which were made by hostel staff caring for him as he suffered a mental breakdown.

Mr Rigg's family have criticised the report for being "ineffective" and "flimsy" in comparison with the inquest jury findings, as well as the initial 2010 investigation.

The report said: "There is no evidence to suggest that the officers who arrested Mr Rigg used excessive force. Conversely however, there is evidence to show that the officers acted reasonably and proportionately during Mr Rigg’s arrest and restraint."

The IPCC has said it will now commission an external review of its investigation.

IPCC commissioner Amerdeep Somal said: "Our investigation commenced the morning after Mr Rigg’s death but was subjected to delays by the decision to interview the arresting officers under caution and complicated by our lengthy endeavours to obtain medical evidence.

"As I have previously said, clearly there are lessons for the IPCC from the investigation into Mr Rigg’s death and I am therefore pleased the IPCC Chairman, Dame Anne Owers, will be commissioning an external review of our investigation to identify areas of improvement."

Mr Rigg's family said: "For the IPCC to conclude in its findings that ‘the officers adhered to policy and good practice by monitoring Mr Rigg in the back of the van’ is absolutely absurd, flies in the face of the evidence and clearly contradicts the jury's narrative verdict.

"The family therefore welcome an external review of the IPCC’s original investigation by someone that is truly independent.

"However, we absolutely insist that the review is a root and branch examination of the IPCC’s investigation and that it is transparent, robust and effective, so that officers are made accountable for Sean’s death."

The IPCC also said two officers are under investigation over their evidence to the inquest and investigators.

This includes Sergeant Paul White, whose evidence was contradicted when CCTV evidence was played during the inquest.

An overall review of deaths in police contact is being conducted by the IPCC in September.