When Herb Farm’s owner Herb Gherbo was arrested in October, his company received a letter informing them that they were under investigation.

Gherbos arrest came less than a month after another Colorado marijuana grower, Kevin Gherbauer, was arrested for the same crime, and the DEA has also been cracking down on the industry.

Now, according to local CBS affiliate KMGH, investigators with the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) have opened an investigation into Gherbebs alleged role in growing and selling marijuana.

According to an ATF spokesperson, Gherbes activity at Herb Farm is under review by the bureau’s Special Agent in Charge, who has notified him that the investigation is ongoing.

The spokesperson told the station that the matter will be referred to the U.S. Attorney’s Office.

Marijuana advocates, however, believe the investigation into Herb Ghers alleged role at HerbFarm is more of a political attack on the state of Colorado, rather than a true investigation into the plant.

Gherbats activity at the herb farm has been widely reported since his arrest in October.

A video that went viral shows the grower planting seeds on his lawn in a matter of minutes, before a neighbor calls the police and says he saw Gherbs hand over money and weed to a stranger.

“He was planting the seeds in a small area,” the neighbor said, according, KMGH.

“I had to go get him because he was planting so fast and it was going to kill the weed.”

In October, Ghers brother, Mark, also came under fire for allegedly planting marijuana in the home of a friend.

The incident led to the arrest of his brother on charges of conspiracy to possess with intent to distribute marijuana, conspiracy to violate the Controlled Substances Act, and a charge of possession of marijuana with intent of trafficking.

Ghers family, however have insisted that the charges were a result of the brother’s involvement in a “sting operation” against his brother.

Mark Gherba’s family also told KMGH that they have a strong relationship with their brother, and that he has no ties to the marijuana grow operation.GHerbats arrest comes at a time when the cannabis industry is also struggling.

The number of states legalizing recreational marijuana use has grown from five to 17, and it remains to be seen if the legalization movement can bring in more jobs or profits for marijuana growers.

Monsanto, for one, says the weed industry needs to diversify to make money and ensure that it is “a good business,” adding that the company’s supply chain is not the same as its competitors.