The mystery continues into where 60 kilograms of military-grade explosives unearthed on an acreage north of Saskatoon earlier this month came from.

CFB Dundurn, 27 kilometres south of Saskatoon, used to have a supply of the same German-made DM-12 plastic explosives found buried on the Martensville property, but its explosives have all been accounted for, a spokeswoman for the Canadian Forces says.

"When we heard about this story, we went back in our records to see when was the last time we had them, how many did we have and how they were disposed of," Anne Genier of the Canadian Forces said.

However, the last 276 kilograms of the plastic explosive were blown up in 1999, she said.

"We disposed of them because they were obsolete," Genier said.

The land the explosives were buried on belonged to Ian Finlay, a former Saskatoon police officer who died of heart disease in October.

Staff Sgt. Grant Obst, who ran the Saskatoon Police Service's bomb squad in the 1990s, said the service has never used plastic explosives like DM-12 or ever seized anything in that amount.

Experts have told CBC it's unlikely the explosives came from mining, construction or demolition companies -- which simply don't use Second World War vintage plastic explosives.

And so, the RCMP continues its investigation. No charges have been laid.