DELAWARE -- A metal building just outside Delaware was a waypoint for hundreds of pounds of high-grade marijuana headed for Chicago, immigration officials said.

Agents with the U.S. Bureau of Immigration and Customs Enforcement and state narcotics officers raided the building May 16 after intercepting a shipping container crossing the Canadian border.

They then arrested two Canadians and an American who allegedly picked up the pot after it was moved to Chicago.

Daniel Francis Berger, 40 of Hinsdale, Ill., and Canadians David Anthony Downing, 32, and Azar Berend Niekamp, 30, were charged with conspiracy to defraud the United States in connection with the drug operation in U.S. District Court in Cedar Rapids.

Agents seized 600 pounds hydroponically grown marijuana that was produced in British Columbia, Canada, that goes by the street name "BC Bud," according to court records.

"BC Bud" is more potent than traditional marijuana.

The British Columbia product has a THC content of about 25 percent, according to information from the U.S. Department of Justice's National Drug Intelligence Center. THC, or tetrahydrocannabinol, is the main active ingredient in cannabis plants like marijuana. Mexican-grown marijuana, which is more common in the United States, has a THC content of about 4 to 6 percent, according to the center's numbers.

The Canadian pot can fetch prices in the range of $3,000 per pound or more in the United States, according to figures from the National Drug Intelligence Center and the Drug Enforcement Administration.

This would place the value of the May seizure at more than $1.8 million.

Officers started the investigation May 14 when a Canadian semitrailer was stopped at the crossing near Pembina, N.D.

The driver said the shipping container he was carrying was empty, but Customs and Border Protection officers found the 600 pounds of marijuana hidden in the container's walls, according to court records filed by ICE agents.

Officials determined the driver and the shipping company weren't aware of the contraband, and they arranged to have the shipment continue to its destination in Iowa, court records state.

The trailer and shipping container were left at a Delaware, Iowa, truck stop, and on May 16, another semi hooked up to it and pulled it to a metal building about a quarter mile outside the city, which is just off U.S. Highway 20 east of Manchester.

When authorities raided the property, they found three people inside. Officers learned that an earlier shipment of 600 pounds of marijuana had come to the building for delivery in Chicago in late April.

One of the people that agents found agreed to help with the investigation as an informant. He drove to Chicago while being watched by officers and met Downing. Downing took the vehicle to an address where he apparently unloaded some of the marijuana and then returned the vehicle to the informant, records state.

Next, the informant met Berger and Niekamp in a parking lot, and they took the vehicle, records state. As officers followed, Berger and Niekamp began driving down side streets in an apparent attempt to see if they were being tailed, records state.

Finally Burger stopped and attempted to flee on foot but was captured, records state.

All three were served with federal arrest warrants May 19. Berger was released, and the other two remain in custody in Illinois. They have court hearings next week.

Although most imported marijuana comes to the United States from the Mexican border, drug seizure data show the amount of marijuana smuggled in from Canada has risen, according to the National Drug Intelligence Center's threat assessment for 2007.

In fact, the quantity of marijuana seized increased 129 percent in a five-year period from 11,546 kilograms in 2001 to 26,414 kilograms in 2005, the report states.

Contact Jeff Reinitz at (319) 291-1578 or jeff.reinitz@wcfcourier.com.