Two National Guard members have been identified who appeared in risqué photos and videos being used to create a calendar, The Associated Press reports.

The Hot Shots calendars have been produced since 2009. A percentage of the profits from their sales goes to war veteran charities. This year the charity is Help for Heroes, according to the hotshotscalendar.com website.

The problem is that the two National Guard members seen in the shoot may have lent military equipment to the production crew without authorization, and violated National Guard policies by appearing in the videos in uniform.

The Guard is now conducting an investigation.

A senior non-commissioned officer from the 19th Special Forces Group allowed the production crew onto National Guard premises at Camp Williams, a decision he was not authorized to make, according to Desert News.

“No payments were received by any Utah National Guard members for support or involvement in the production of the calendar,” said Lt. Col. Steven Fairbourn, according to the website.

On Friday, Fairbourn said that no military equipment was used by the Hot Shots Calendar personnel in their production. However, a video posted by Hot Shots Calendar to YouTube shows many different types of weapons, including machine guns and an armored personnel carrier. Investigators plan to uncover where that equipment came from.

Much of the video was shot at a private gun club called Big Shot Ranch in Grantsville, UT. Big Shot Ranch employee Nikko Kelaidis, according to Fox News, could not tell if the guns used in the video were borrowed from the gun club, but knows the tank does not belong to it.