A holiday-maker who died in a Brazilian police cell of a suspected drug overdose may have been beaten to death, a new investigation shows.

Neil Juwaheer, 35, died in custody while on holiday in northern Brazil in July 2007 after local police claimed he swallowed a package of cocaine.

But an independent investigation funded by Mr Juhaweer’s parents, who own Croydon care home Thornton Lodge and live in Carshalton Beeches, revealed that the former estate agent died of severe head trauma.

Respected Brazilian coroner Dr George Sanguinetti reinvestigated the original pathologist’s reports into the death of Mr Juhaweer, who used to live in South Croydon but shared the family home up to his death, and found massive inconsistencies.

He told the Guardian: “The language of the deceased’s body told me he was beaten to death and suffered several traumas, including severe head trauma.

“What was declared in the original report was not true. His death was a result of severe trauma to the head and other parts of his body and not a cocaine overdose.”

His damning evidence has forced federal prosecutors at the Brazilian Public Ministry to last month reopen the case and call on police for answers.

At the time tourism police chief Milena Monteiro said doctors found no evidence of police abuse, such as marks or injuries on his body.

Mr Juwaheer was arrested in the north-eastern city of Fortaleza on suspicion of burglary during a month-long holiday in 2007.

The former estate agent, listed as co-director of dating website Brazilian Girls 4U Ltd, was said to have jumped or climbed over a wall of private apartments and collapsed an hour after being taken into custody.

Mr Juwaheer’s parents, Chatrapal, known as Joe, and Pauline, who lived in Carshalton Beeches with their son at the time of his death, hired Dr Sanguinetti and Brazilian lawyer Marco Martins, in August as part of their bid to reopen the case.

Employees at Thornton Lodge said the couple, who are believed to have two other children, have been “distressed and ill’’ since their son died.

Neighbours along Pine Walk said they had never accepted Mr Juwaheer had died of a drug overdose and said he was a “fit healthy young man’’.

Human Rights Commission of the Order of Brazilian lawyers, Dr Hélio Leitão said: “After the family got in touch with us we believed that the case needed further investigation.

“I cannot comment on the details now. We now need to wait for a decision of the Public Ministry on whether charges will be brought against whoever did this or not.’’

Carshalton and Wallington MP Tom Brake said he was taking the case up with the Foreign and Commonwealth Office and would question the level of support given to British citizens abroad.

This week Chief Monteiro claimed police had been “transparent’’ in their investigation.

She said witnesses were certain Mr Juwaheer was under the influence of something, “most likely drugs’’.

She said: “Since the process reopened we are more than happy to conduct more interviews and get more relevant statements, as needed.

“We have done everything we could to help at the time of the death.’’