A Canadian Forces officer says the Department of Defense might release more information about the helicopters at a later date.
The Defense Department acquired the MI-17 helicopters for combat use in Afghanistan but has refused to provide details about how much the deal cost taxpayers or how many aircraft are operating, Postmedia News reported.
The military says the lease was the result of a competitive contract but the details were not published on the MERX Web site, which formally lists such information, the report said.
Military officials said releasing the helicopter information now could help Afghan insurgents.
The new helicopters have been used in Kandahar province since spring and are among tens of millions of dollars worth of equipment to be used in Afghanistan the Defense Department has kept secret, sources told Postmedia.
A spokeswoman for Canadian Forces, Navy Lt. Kelly Rozenberg-Payne, said the cost of the lease might be made public later. She said the helicopters were requested by commanders in Afghanistan.
"The (operational) tempo within the air wing became very great and it was just assessed by commanders on the ground that they needed additional platforms to help move troops around," she said.
Canada operates Chinook helicopters in Kandahar and leases helicopters from Toronto-based Skylink Aviation. It also operates its own Griffon helicopters.