WINNIPEG - Police say a nine-month-old boy found in critical condition in a Winnipeg home last month ingested a powerful drug called carfentanil that has recently turned up in the city.

Powder found at the scene was believed to be fentanyl, but tests show it was the much more powerful drug -- a synthetic opioid that can be fatal in very small doses.

The infant's condition has improved.

Const. Jason Michalyshen says it's not clear how the child ingested the drug.

But he adds kids are curious and there are a number of ways in which a small amount can get into a child's system.

The boy's parents have been charged with failure to provide the necessities of life, criminal negligence causing bodily harm and possession for the purpose of trafficking.