DENVER -- A Canadian national found dead inside an upscale Denver hotel with a pound of highly toxic sodium cyanide had killed himself, the deputy coroner said Wednesday.

However, a spokesman for Dirie's family said he finds the idea that it was suicide "ridiculous."

Saleman Abdirahman Dirie, 29, was found dead inside the Burnsley hotel on Aug. 11. In his hotel room, firefighters found nearly a pound of sodium cyanide -- the crystal form of cyanide.

"This office completed an autopsy. The test results have been returned to our office and the decedent was positive for ingesting cyanide. The manner of death is suicide," said Denver Chief Deputy Coroner Michelle Weiss-Samaras.

Family members told reporters that Dirie, a Somali refugee, had been depressed and suffered from schizophrenia. However, Omar Jamal, executive director of the Somali Justice Advocacy Center, said he "strongly disagrees" with the coroner's ruling.

"The Advocacy Center is still involved in this case and finds the suicide idea ridiculous. If Mr. Dirie's intention was to commit suicide, he could have done so in Canada," Jamal said. "The community finds this recent ruling very strange. I am saddened and still puzzled by this ruling and hope we will go to the bottom of the case soon."

With the approaching Democratic National Convention, there were fears that Dirie's death may have been part of a terrorism plot. The FBI's terrorism task force was called in to investigate, but FBI spokeswoman Kathy Wright told 7NEWS there was no apparent connection to terrorism. Denver police said Dirie's death is an isolated incident and no foul play is suspected.

Investigators still have not said how Dirie obtained the cyanide, how he came to the United States, and why the Ottawa man was staying at a luxury hotel in Denver.

Dirie, a Muslim, was buried last Thursday after a service at the Colorado Muslim Society's Abu Baker mosque.

Jamal said Dirie was unemployed and not particularly religious.

"He had no money. Whoever gave him the money for that hotel may have also given him the cyanide. We need to find that person," Jamal told the Denver Post.

However, Denver police spokesman John White assured that the kind of cyanide Dirie had could be purchased anywhere, since it's the primary ingredient in rat poison.

Dirie told family members that he was going to Denver for vacation. Dirie's sister told CanWest News Service that her brother had been on medication for the past three years to treat his schizophrenia, but that he was not a terrorist.

He was dead for six days inside Room 408 before he was discovered. After the coroner alerted police that cyanide was suspected, firefighters and hazmat crews shut down the hotel for hours and cordoned off the neighborhood.

Cyanide could be fatal if it is inhaled, ingested or touched. It prevents the body from processing oxygen, so it can quickly damage the heart, brain and other organs. It can also be used as a chemical weapon and was used as a genocidal agent by the Nazis in World War II, according to the Centers for Disease Control and Prevention.

The upscale Burnsley Hotel is about two miles away from the Pepsi Center, where the DNC will be held from Aug. 25-Aug. 27. However, it is not on the list of hotels where delegates are staying.