While initial forensic tests indicated Woolmer was likely poisoned in a Kingston hotel March 18, the source told the Times of London that the coach of the Pakistan national cricket team had ingested a deadly amount of the herbicide.
The report said that traces of the weed killer were found in both the inside and outside of a champagne glass inside Woolmer's room.
"Everything was contaminated," the source said. "The stomach content, the glass, everything. There was enough to kill him."
The source said that the weed killer was not available for purchase in Jamaica, the Times reported.
While some forms of weed killer have no smell or taste, a poisons expert from Britain said the item's use is extremely rare in relation to homicide.
The report said it had yet to be determined whether the deadly chemical had found its way into the champagne bottle as well.