The chemical, PMMA, has been blamed for at least one recent Vancouver-area overdose and five more in Calgary.
The coroner is now working with health and police officials to investigate the prevalence of the chemical, which officials say likely originated in the Lower Mainland.
"The higher-level picture is that B.C. would be the manufacturing hub," said RCMP Sgt. Duncan Pound, noting there is no definitive evidence linking the tablets consumed in Calgary to those in B.C.
"We do see distribution going eastward across Canada."
B.C.'s provincial health officer said Thursday officials are concerned "without hesitation" over the finding that paramethoxymethamphetamine — a synthetic compound known as PMMA — has been discovered laced into already dangerous drugs in the two provinces.
A spate of new deaths has recently occurred in both B.C. and Alberta.
Perry Kendall said the coroner's investigation will show whether the chemical has been present in previous B.C. deaths, although Pound said he's not aware of any past cases.
Pound said there are on average 20 deaths from ecstasy in British Columbia per year, meaning last year fell below the average.
The B.C. Coroner's Service did not return a request for an interview.
Alberta's chief medical examiner said earlier this week that PMMA had not previously been associated with street drugs sold in Calgary.
The chemical is thought to be less expensive and can be used to make a drug that appears similar to ecstasy, the officials said in a warning released by the city on Wednesday.
Because it takes effect more slowly than ecstasy's usual ingredient, called MDMA, users may take more to achieve its hallucinogenic properties, Kendall said.
"They think it's not happening, the onset is also rather mild to start with, so they start taking more pills because they think that they got lower doses and they end up with more significant overdoses," he told reporters.
"That's a possible explanation for some of the deaths we've seen here or in Calgary."
The chemical is considerably more toxic, interfering with serotonin metabolism in the brain and raising the body temperature, which can lead to irreversible brain and organ damage, Kendall said.
He cautioned there is no such thing as a safe street drug, noting RCMP tests in B.C. over recent years have shown ecstasy is made of a cocktail of chemicals. Other ingredients can include methamphentamine, katamine, horse tranquilizer, caffeine and talcum powder.
But Pound said even as the coroner's office does its work, it's not likely any new police probe will be launched to specifically target operations cooking up the lethal drug.
"Would it even be possible to have investigations specific to PMMA? That's unlikely because we're . . . already targeting clandestine labs."
RCMP took down more than 30 labs in B.C. last year, he said, including meth labs that also made ecstasy.
Since late November, three people in B.C.'s Lower Mainland have died and a fourth went to hospital in critical condition after taking pills they believed to be ecstasy.
Abbotsford 20-year-old Tyler Miller died on Nov. 27 while partying with friends in Langley. It was the first case in the region in some time and prompted public warnings from his parents, who knew he had taken the drug before.
Just over three weeks later, 17-year-old Cheryl McCormack died a few days after taking ecstasy with girlfriends at a sleepover in Abbotsford. Police said she was hoping the pills would help her lose weight.
Another Abbotsford woman, 24, who consumed the drug for recreation at a New Year's Eve party only started to show "positive signs" of recovery on Thursday after her near-death experience, said Const. Ian MacDonald of Abbotsford police.
Last Sunday, a 22-year-old woman had a fatal reaction to the drug police said she took willingly at a house party in Vancouver.
In all the three cases involving women, friends of the victim also took the drug but did not suffer the same consequences.
Police have not released the names of the people who died in Calgary for privacy reasons.
Ecstasy comes cheap, sometimes only costing $5 or $10, and is popular among young adults in the party scene, according to the RCMP.
MacDonald said police are gathering as much information as possible and are trying to determine whether it might be being sold at discounted rates or passed out for free.
After speaking to the mother of the 24-year-old who is still in hospital Thursday morning, he said she and police share the same view about the potential for a new chemical to be making rounds.
"It doesn't matter, because at the end of the day young people are ingesting something that they really have no knowledge of," he said.
"They don't know what it's going to do to them. They've created real or perceived expectations around it, but they don't know."