Aon broker Hugh FitzRoy Newdegate, 37, was found dead from a suspected heroin overdose last week in a five-star hotel in the Burmese capital, Rangoon.
His body was discovered by staff at the Traders Hotel in Rangoon on the morning of Friday, March 3. He is believed to have been on a business trip in the city.
FiztRoy Newdegate was the brother of Viscount Daventry. News of his death comes just one month after that of his father Francis Newdegate, 78, on February 15 following a long illness.
Worried staff at the hotel had unlocked his room after the Eton-educated aviation broker failed to answer an overseas phone call.
A packet containing 0.02 grams of heroin was found in a drawer at his bedside, according to Burma state newspaper the New Light of Myanmar.
A Foreign Office spokeswoman said: "He had not been seen since noon on Thursday. When found by the hotel doctor, he was pronounced dead. The Burmese police are conducting an investigation."
The newspaper said that an investigation by a forensic doctor from the Rangoon General Hospital found the cause of death to be a drug overdose. But the Foreign Office spokeswoman said: "There has been an autopsy, the results are not yet known, and we cannot speculate about the cause of death."
A statement from Aon Group read: "We are all devastated. We have been advised of nothing to suggest this was anything other than a tragic accident. Hugh will be greatly missed by all his many friends and colleagues throughout the world. The entire Aon Group, but particularly the Aviation Company, extend our deepest sympathy to Hugh's family."
A spokesman for FitzRoy Newdegate's family, said: "His family are utterly devastated at reports of his accidental death. This has come as an awful shock to everyone who knew him."