Twelve people were arrested Thursday after raids at eight different locations of a popular Denver pot shop due to staff there selling more marijuana than is allowed by law, police said.

All 26 marijuana licenses held by Sweet Leaf dispensaries in town were suspended for selling more than an ounce of pot - the legal limit - to its customers, according to the Denver Department of Excise and Licenses.

Per Amendment 64 to the state constitution, which legalized the sale and use of recreational marijuana in Colorado, pot shops are only allowed to sell an ounce of weed to a customer per day.

In its ruling, the department found, "Reasonable grounds and probable cause exists to believe that Respondents have engaged in deliberate and willful violations of state and local laws or regulations, and/or that public health, safety, and welfare requires emergency action."

Denver Police, along with other agencies, raided eight storefronts belonging to the Sweet Leaf family all over town after a year-long investigation into the company. Police did not explain how much above the legal limit these employees are accused of selling.

Twelve suspects are being held for "investigation of illegal distribution of marijuana," DPD said. The booking process is still underway for the suspects, so their names and mugshots aren't available at the time of this writing.

The locations raided were:

1475 S. Acoma St. - Denver
2647 W. 38th Ave. - Denver
5100 W. 38th Ave. - Denver
4400 E. Evans Ave. - Denver
2609 Walnut St - Denver
4125 N. Elati St. - Denver
7200 E. Smith St. - Denver
15200 E. 6th Ave. -Aurora

The first listed storefront isn't a pot shop, but a place where Sweet Leaf conducts "business," DPD said.

A sign taped to the front door of Sweet Leaf, a medical and retail marijuana chain in Denver, confirms its marijuana retail licenses have been suspended.

The sign reads:

"Notice of Suspension: Medical and/or retail marijuana licenses for these premises have been suspended by order of the Denver Department of Excise and Licenses for alleged violations of Colorado law."

Another hand-written sign next to the printed sign from the City of Denver says, "Sorry, we are closed."

sweet leaf closed_1513284276363.jpeg.jpg
Sweet Leaf Marijuana, Thursday Dec. 14, 2017.

The sign was posted at the store's Walnut Street location, but each Sweet Leaf location is now closed as long as its licenses are suspended.

Dan Rowland, a spokesperson for the city's excise and license department, said this is the first time Denver's suspended a marijuana license like this.

"There has been discipline taken against marijuana business in the past, fines - fees - things of that nature - never a summary suspension like this," Rowland said.

Sweet Leaf released a statement to 9NEWS via Twitter. It reads:

Official Sweet Leaf press statement "This morning, Sweet Leaf was surprised to receive notification from the Department of Excise and License suspending all of our city licenses in the City and County of Denver. It is unclear at this point exactly what actions, if any, Sweet Leaf took to cause the city to issue this order. Sweet Leaf is cooperating with the authorities to resolve this issue and hopes to have all of their stores back in operation as soon as possible."

Sweet Leaf's website lists ten metro Denver locations selling both medical and recreational marijuana.

The company's stores in Portland, Oregon were all reportedly still open.

According to its summary suspension, a hearing on the ruling will be scheduled by the Department of Excise and Licenses within 30 days.

The Colorado Marijuana Enforcement Division, Denver District Attorney's Office, Denver City Attorney's Office, Denver Department of Excise and Licenses, Denver Department of Public Health and Environment and Aurora Police Department all assisted Denver Police in the investigation.