A grieving couple are set to make a breakthrough in their fight for justice for their son, who died in a police cell in Brazil.

Holidaymaker Neil Juwaheer, 35, from Carshalton Beeches, was said to have died of a drug overdose in 2007, but a later pathology report found he was beaten to death.

Now his parents, Joe and Pauline Juwaheer, are sending their DNA to Brazil to be tested against the cocaine wrap allegedly found in their son’s stomach, that Brazilian authorities claim killed him.

The wrap, the one piece of evidence suggesting drug abuse, was lost by Brazilian police for 18 months.

The family’s lawyers suspect the cocaine wrap may have been planted.

It is hoped his parents’ DNA will help prove whether or not it did come from Neil Juwaheer’s body.

Joe Juwaheer, 73, who runs Croydon care home Thornton Lodge, said: “We are doing this to get justice for our son.”

St Bartholomew’s Hospital will take the samples, which will be delivered to Dr George Sanguinetti, the respected Brazilian coroner who concluded Mr Juwaheer suffered a violent death.

His damning evidence forced the investigation in to the death to be re-opened.

He will supervise the tests on the cocaine wrap and the Juwaheers’ DNA.

It is likely, even if the cocaine wrap has a residual sample of Neil Juwaheer’s DNA, the family would not accept it as proof he died of a drug overdose, as the evidence could have been tampered with.

The Juwaheer family’s British lawyer Alan Larkin explained the Brazilian authorities had never been able to explain how the wrap disappeared, or where it was for 18 months.

He said: “Because of the loss of such an important piece of evidence, we are understandably going to great lengths to ensure the DNA is properly delivered.”

It is hoped the DNA could be delivered by the end of the year, although arrangements still need to be finalised by the Juwaheers’ Brazilian lawyer.

Neil 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, was said to have jumped or climbed over a wall of private apartments, and collapsed an hour after being taken into custody.