The Independent Police Complaints Commission (IPCC) is now investigating Kent Police after a Medway man was left in a coma.
The commission initially said it was not investigating why Mr Collins, 38, was left in a coma after he was found in house in Gillingham, in December last year, but has now confirmed it is.
A spokesman for the IPCC said the reason for the U-turn was that it had received 'an assessment of complaints' on behalf of Mr Collins.
Denby Collins in a coma in hospital
Police were called to a house in Lower Rainham Road, on December 15 at about 3.20am after an emergency call from the residents.
When officers arrived they found that at least one of the residents was restraining Mr Collins, who the police arrested as a suspected burglar and handcuffed.
However, Mr Collins was unresponsive and the South East Coast Ambulance Service attended he was taken to Medway Maritime Hospital.
Just last month, Mr Collins was transferred to the Royal Hospital for Neuro-disability in Putney, London, where he remains in a hypoxic coma.
IPCC Commissioner Mary Cunneen said: “This is clearly a difficult time for Mr Collins' family and I have offered to meet with them to explain our investigation.
“My decision to independently investigate follows an assessment of complaints we have received, on behalf of Mr Collins, against the available evidence.
Denby Collins has been in a coma since police handcuffed him
“Our investigation will examine the use of force, including handcuffs, by the officers who attended the scene, the intelligence and information provided to the two initial attending officers and whether the arrest of Mr Collins was justifiable in the circumstances as they presented themselves.
“We will also look at the first aid provided by the officers prior to the arrival of the ambulance service.”
“This is clearly a difficult time for Mr Collins' family and I have offered to meet with them to explain our investigation" - Mary Cunneen
The IPCC also considered complaints from Mr Collins’ family relating to the alleged failures of Kent Police to investigate the injuries he received; the information they provided to his family after the incident and the actions and decisions of the police once Mr Collins was in hospital.
The decision has been taken that these matters can be investigated by the Kent Police themselves.
Kent Police referred the matter to the IPCC on December 15 2013.
IPCC investigators were immediately sent to Gillingham to carry out an initial assessment of the evidence available at that time.
A statement issued by police confirmed the investigation, saying: "Enquiries are ongoing into the circumstances of how he came to be in the house and how he (Mr Collins) came by his injuries.
"Kent Police referred the matter to the IPCC on 15 December.
"The IPCC attended and following an initial investigation of the circumstances determined the matter could be dealt with by Kent Police.
"The IPCC has subsequently decided to conduct an independent investigation.
"Kent Police is cooperating with the IPCC and it would be inappropriate to comment further while this investigation is ongoing."
Police confirmed the officers concerned were on full duties, and hadn't been suspended.
The family of Mr Collins welcomed the IPCC decision to carry out an independent investigation into Kent Police’s conduct at the house he was found in, where the police were responding to a 999 call.
Peter Collins, said “We expect the IPCC to carry out a careful and robust investigation into all aspects of police conduct on that night.”
However, the family of Mr Collins say they are very disappointed that the IPCC have refused to independently examine the complaints about the conduct of the Kent Police investigation into what happened in Lower Rainham Road that night.
The family claim the police appear to have conducted a wholly inadequate investigation into what seems to have been a very serious assault inflicted on Mr Collins, which has left him in a coma six months after he the incident.
Peter Collins, added: “The failure of Kent Police to launch an immediate robust criminal investigation into how Denby sustained such life threatening injuries at the time is deplorable and surely needs a thorough investigation by the IPCC, which should re-think a decision to leave this to Kent Police to investigate themselves.
“The public and the family can have no confidence in such an in-house investigation in such a serious case.
“We also appeal to any member of the public to come forward who can shed some light on this event or Denby’s whereabouts and movements on that night.”
The family also say the Kent Police investigation is no longer considering the apparent assault on Mr Collins, so they want any new evidence examined and investigated by an outside police force, especially given that they say they have lost all confidence in the competence, thoroughness and fairness of Kent Police.