BRECKENRIDGE, Colo. -- The investigation into 200 marijuana plants found in a Summit County home cost the county more than 60 man-hours and $3,000 in investigative costs.

The problem is the plants were legal under the state's medical marijuana law, the Summit Daily reported Monday.

The man growing the plants provided investigators with state-issued registry cards and medical records for about 400 people he is servicing.

"The problem with caregivers is the state doesn't tell us who is a caregiver and who is not," Summit County Sheriff John Minor told the newspaper.

Minor said the investigation began when a citizen turned in a lost camera that contained photos of the marijuana-growing operation. Investigators worked the case and were able to identity the home involved.

By Oct. 16, investigators had enough for a search warrant and seven officers swooped down on the home of the man, who didn't want to be identified.

The caregiver said he provided officers with the paperwork that allowed him to grow up to 2,400 plants legally, for medical purposes, and the officers left an hour later.

Summit County Drug Task Force director Derek Woodman told the Summit Daily that seven of the 10 search warrants served on local marijuana growing operations in the past six months were on locations that turned out to be people who were legally allowed to grow it.

According to Woodman, there's no way for law enforcement officers to confirm a marijuana grower's legality without serving warrants because the state doesn't keep track of caregivers.

Minor said marijuana plants have been valued at up to $5,000 each in civil court, so officers have been forced to water and care for confiscated marijuana plants until their legality is established. That could be a violation of federal drug laws.

"That's the mess that we're in, and we need some clear guidance," Minor said.