In a written statement, a DND spokesperson echoed some of Murphy's statement, and said the department "has policies and practices in place to deter, detect and enforce unauthorized and prohibited computer use."

The spokesperson, Ashley Lemire, also pointed to an internal military policy outlining responsible online use.

"DND employees and CAF members must ensure they maintain the highest ethical standards and values in all uses of the Internet, the defence intranet, computers and other IT systems," says the internal directive.

The U.S. military considers adultery a chargeable offence under regulations, but there is no such provision under Canadian military law.

National Defence would not say whether it's investigating who accessed the Ashley Madison site.

Toronto-based Avid Life Media, the parent company of Ashley Madison, says the company doesn't store full credit-card data from members.

Hackers this week released detailed records on millions of people registered with the website one month after the break-in at Avid Life Media. The website — with its slogan "Life is short. Have an affair" — is marketed to facilitate extramarital affairs.

The credit-card information of U.S. government workers — some with sensitive jobs in the White House, Congress and the Justice Department — was also revealed in the data breach.

"I was doing some things I shouldn't have been doing," a Justice Department investigator told the Associated Press.

Asked about the threat of blackmail, the investigator said if prompted he would reveal his actions to his family and employer to prevent it.

Defense Secretary Ash Carter said the Pentagon was looking into the list of people who used military email addresses. Adultery can be a criminal offence under the Uniform Code of Military Justice.

The Canadian Press