DENVER (AP) — Some 4,200 medical marijuana applications in Colorado are on hold at the state health department while investigators look at possible fraud.

The Colorado Department of Public Health and Environment announced Friday that marijuana registry applications from certain physicians are on hold after law enforcement witnessed potential patients being seen by someone other than a physician. Colorado law requires a “bona fide” doctor-patient relationship before a physician can recommend pot for certain ailments.

READ MORE: Contractors Say CDOT Is Hiding Costs Of Big Contracts With Out-Of-State Companies

In 2010, state lawmakers tightened the requirement to state that a physician must perform a personal physical examination, keep records of the visit and offer follow-up care. Lawmakers were concerned about possible fraudulent recommendations.

READ MORE: 'If Roots Don't Get Moisture, They Die': Experts Say To Water Landscaping As Colorado Faces Abnormal Warm And Dry Spell

The health department said Friday that the applicants on hold would receive an answer by the end of January.

MORE NEWS: Booking Booster Shots Proves Challenging For Some Coloradans

(© Copyright 2011 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)