Canada's navy plans to spend about $120 million to upgrade 36 torpedoes, but they still won't work in its four submarines without further refits, CBC News has learned.

The navy has MK-48 American torpedoes in stock, but the four British-built submarines aren't capable of firing them.

Even after the weapons are converted, Canada would still have to spend millions more to refit the submarines to fire them.

Defence Minister Peter MacKay confirmed the plans on Friday but said no decision had been made about the procurement.

"Of course I know about it," MacKay said during a campaign stop with Conservative MP Gerald Keddy in Bridgewater, N.S.

"There's absolutely no decision taken at this point. The Department of National Defence is continuously looking at different procurements whether it be munitions, whether it be new equipment."

U.S. disclosed purchase

Canada's plan to upgrade the torpedoes was revealed by the U.S. Defence Security Co-operation Agency, which oversees arms sales to foreign countries. The agency said the equipment, parts, training and support would cost more than $120 million Cdn. It notified the U.S. Congress about the sale in mid-March.

Since Canada already has the torpedoes, it will have "no difficulty absorbing these additional conversion kits," the agency said in a new release.

Canadian Defence Department officials have yet to respond to questions from CBC News.

MacKay insisted the vessels are good submarines and said it had been a "challenging effort" to upgrade them.

'I’m not surprised for a minute that they once again tried to hide and deny another misspending adventure'—Liberal MP Dominic LeBlanc

"They do participate in trials, we don't talk about their location, we don't talk in some cases about the missions that they're on, but I can assure you — they're very versatile, they're very useful to Canada and they're very useful for protecting our coastline and our water approaches," he said.

Liberal MP Dominic LeBlanc said the naval controversy seems to be have parallels to the troubled purchase of F-35 fighter jets.

That the new costs for the torpedoes were revealed by a U.S. government agency — and not the Department of National Defence — is also troubling, he said.

“I’m not surprised for a minute that they once again tried to hide and deny another misspending adventure, because they got caught with egg on their face on the fighter jets. Their first instinct is always to hide and deny and bury this information,” LeBlanc said.

LeBlanc said a Liberal government would undertake an immediate review of all procurement policies.

Scott Taylor, publisher of Esprit de Corps, a military magazine, said the navy's submarine program has become an expensive national embarrassment.

"This is probably a little more icing on a cake we probably should never have had," he said.

HMCS Windsor remains in drydock for repairs. (CBC)

"Upgrading armaments on submarines, which have never really patrolled, with no war imminent — I mean people have got to be questioning that."

The British Royal Navy launched the Upholder-class, diesel-powered submarines in the late 1980s and withdrew them from service in 1994. Canada bought four of them in 1998 and renamed them Victoria-class.

The submarines have been plagued with problems. Only HMCS Corner Brook is partially operational.

HMCS Chicoutimi caught fire on its first voyage in 2004, resulting in the death of naval lieutenant Chris Saunders. It won't be ready for sea until next year.

The repairs on HMCS Windsor are costing millions more and taking years longer than expected. The submarine won't be fully operational until 2013.

The refit of HMCS Victoria continues, though it was expected to be back in the water late last year.