After years of investigation by conservation officials, four men have been charged for their roles in widespread illegal killing of trophy deer and other big game in western Minnesota.

The five-year probe by the state Department of Natural Resources (DNR) led to the seizure of dozens of guns, some of them high-powered rifles, and more than two dozen sets of deer and elk antlers, the agency announced Tuesday.

The DNR's Capt. Cory Palmer said he's never seen such an extreme case of poaching in his 17 years with the agency.

"This is taking away from hunters and people who just want to watch deer," said Palmer, himself a deer hunter.

Charged last week with the bulk of the counts in Lac qui Parle County District Court was Joshua Liebl, 37, of Dawson, Minn. Under a multistate enforcement compact, Liebl lost his hunting privileges in Minnesota in 2013 because of a shining conviction in South Dakota.

Liebl faces gross misdemeanor and misdemeanor charges that include transporting illegally taken big game, using artificial light while hunting, hunting at a prohibited time, trespassing and failure to register deer.

Palmer said there are no felony charges for what Liebl is accused of doing. If convicted, Palmer added, Liebl faces several years of losing his license along with fines and restitution.

On Oct. 21, officials seized at Liebl's home 37 guns, 28 sets of deer antlers (most of trophy quality), four sets of elk antlers, a set of mule deer antlers and a fully intact piebald deer in the freezer. Piebald deer are known for their large white and darker-colored patches.

DNR Lt. Gary Nordseth said that Liebl has registered no more than four deer since 2004.

Authorities said they also pulled over Liebl near his home in a pickup truck as the confiscations were underway. In back of the truck was a freshly killed eight-point whitetail buck, which investigators determined was killed with a high-powered rifle.

Also seized from the truck were a scoped rifle, a shotgun, rounds of ammunition and a spotlight. The truck is now destined for the auction block, with proceeds going to the DNR's Game and Fish Fund.

Dustin Shourds, the regional director for the Minnesota Deer Hunters Association in Montevideo, said "everybody heard rumors about" Liebl "at the barbershop and that kind of thing. When it all came down, it was quite a shock."

Also charged with gross misdemeanors or misdemeanors in connection with the case were:

Kevin J. Martinson, 58, of Plymouth, accused of illegally lending or borrowing a deer license.

Nathan J. Viessman, 32, of Watson, Minn., accused of illegal party hunting, lending or borrowing a deer license, exceeding the limit of deer taken and failure to register deer.

Daniel J. Lien, 33, of Dawson, a passenger in Liebl's truck when it was stopped, accused of aiding and abetting unlawful transportation of big game.

Messages were left Tuesday with the defendants; Viessman said he was unaware of the charges and declined to comment.