Interim PC leader Ric McIver says he can't explain why his former government rejected $1.4 million in drug treatment funding from the federal government. 

Documents obtained by CBC News show Alberta Health sought approval from Health Canada for the funding, but then rejected it in March 2015 in the midst of the fentanyl crisis.

McIver says he can't speculate on why the unconditional money was turned down.

"It would appear from the documents released that money was not taken when it could have been. The big question is why? I don't have that answer, but I'm certainly interested in it," he said.

The NDP government says it has restarted negotiations with the federal government to fund new programs under Ottawa's Anti-Drug Strategy Initiative.