Police officials and federal agents have arrested more than 40 people and seized piles of pot plants and growing equipment around Denver area in Colorado. The raids were part of a multi-state investigation regarding illegal distribution of marijuana outside the state.

In a report by ABC News, the raids took place on Thursday. Most of the people arrested are said to be drug traffickers seeking safe haven in the state as the marijuana industry in the area is flourishing. These people are accused of shipping the drug out of state where it can sell for more than double as opposed to the price in the state.

Accordingly, the investigation before the raids took place lasted for a year. The investigation began when residents living near the growers complained about the smell of weed. An official familiar with the case, who asked to be anonymous as the investigation is ongoing, added that the people involved in the raids moved to Colorado from Texas specifically to grow marijuana, Chicago Tribune reported.

More than 30 properties were raided in Denver's southern area as well as in Colorado Springs.  At one of the homes raided, agents were able to confiscate grow lights. Large pot branches were also stacked in bushy piles outside a trailer. At another home in Centennial, drug agents were able to find more than 300 plants.

Not all the raids were made effortlessly as CBS News reported that in one location in Monument near Colorado Springs, a person barricaded himself inside a building. Police were then forced to use tear gas in order to have him extracted.

Most of the drug traffickers hid among the state's sanctioned warehouses and farms. Others live in neighborhoods wherein concerned neighbors tip police officials with their illegal activities.

In the recent weeks, several other raids were carried out. Last month, the raid focused on unlicensed pot growers. 12 people were arrested in Pueblo during seven separate investigations. The people arrested were from Florida but were originally from Cuba.