The family of a man who died after taking a performance-enhancing drug used by bodybuilders to help burn off fat have spoken of their loss of a "fun, loving and caring" man.
Sean Cleathero is believed to have died after taking the substance 2, 4-Dinitrophenol, (DNP) which he got from a local gym, according to police.
Thames Valley Police is investigating after the coroner's office referred the death of the 28-year-old.
The father-of-one was taken ill and died at hospital in High Wycombe, Buckinghamshire, on Wednesday.
The death is being treated as unexplained.
His family said in a statement: "Sean was very loved and popular. His death has come as a complete shock to his family and friends. He was a fun, loving, caring son, grandson, brother and nephew.
"As a father he leaves behind a three-year-old daughter who will carry on his infectious personality which made him so popular to all of his friends and those who knew him."
A police spokesman said: "His death was referred to Thames Valley Police by the coroner's office on Wednesday. It is believed he may have taken a substance called 2, 4-Dinitrophenol, which is believed to be a performance enhancing drug which he got from a local gym."
The spokesman added that a post-mortem examination was inconclusive. The spokesman said: "The investigation into the cause of death continues and further tests are required. Police are currently exploring any potential link between the drug and the man's death but while the investigation progresses is advising anyone who may have bought DNP tablets through unofficial sources, not to take them."
DNP is used to help burn fat but can have side effects such as extreme body temperatures leading to brain damage and blindness.