"If you were to put these keys into your computer now there's no [file] extension that comes on the files. You would not be able to identify exactly what software you would need to utilize them."

"There is no evidence that copies of personal information on two USB keys have been improperly accessed," he added, but out of "an abundance of caution" is telling the public now.

The USB drives had been to transfer data to laptops in a temporarily leased building where Elections Ontario was updating the voter registry. Laptops used by staff didn't have Internet access to the government's servers.

Staff were told to lock up the drives when they weren't in use.

Two civil servants who had responsibility for the drives are no longer with Elections Ontario, the chief elections officer said. Once the investigations are finished other actions may be taken, he added.