The toxicology results of Bob Woolmer have reportedly shown presence of a foreign chemical substance in his system.
"A foreign chemical substance has been discovered in Bob Woolmer's blood and tissue samples, the toxicology results have reportedly stated," according to a newspaper report.
"According to a well-placed government official, the substance, believed to be poison, was found in samples taken from the coach's stomach, urine and blood," The Jamaican Gleaner said.
Deputy Commissioner of Police Mark Shields had confirmed on Saturday the receipt of the toxicology report, but refused to comment on the contents.
The police said they would be relying on histology and toxicology analysis of Woolmer's tissue sample to give them an idea of the events leading to the coach's death.
"The histology is back. I have not seen it, but it is the toxicology that we are still working on... The toxicology is much more important," Assistant Commissioner of Police Les Green said.
The report also said that help has been sought from Scotland Yard in the analysis of the results.
Histology results will help the pathologist to arrive at a time of death, which has not yet been established, while the toxicology should justify or rebut speculations that the 6ft 1in, 250-pound Woolmer was poisoned before being strangled by his unknown attacker or attackers, the report said.
Meanwhile, some members of the Pakistan team may be asked to make their way back to Jamaica for the Coroner's inquest which begins next Monday.
ACP Green said Coroner Patrick Murphy had made it clear that he wanted members of that delegation back for the inquest.
Kent Pantry, the Director of Public Prosecutions, and Murphy are to meet later this week to decide the list of witnesses for the inquest.
Woolmer, 58, the Pakistan cricket team coach, was murdered in his Jamaica Pegasus hotel room four weeks ago.