More than 300 marijuana plants were discovered and seized about an hour's drive northeast of the Twin Cities during a bust that law enforcement called a "very sophisticated" operation.

The plants were found Friday at a barn just off of Hwy. 63 in Comstock, Wis., according to the Barron County Sheriff's Office.

"Located ... were over 300 marijuana plants and a very sophisticated growing operation enclosed in a barn," a statement from the office read.

Michael Haney, 37, who lived at that address, was arrested and being held on marijuana production charges.

"This one was a pretty high-tech operation inside of a barn where they literally built another building inside of the top part of the barn to mask the smell and help assist with the grow operation," Sheriff Chris Fitzgerald told WEAU-TV in Eau Claire.

Fitzgerald said numerous animals were also found on the property including two monkeys, the TV station reported, which are now being cared for by a friend of Haney's.

Deputies with sheriff's offices from Barron, Washburn and Rusk counties were joined by members of the state Department of Investigation in keeping watch on the property for a month until the bust was made.