SCITUATE — The state police said on Thursday that members of a drug task force were able to track a shipment of marijuana and seized 1,500 pounds of it when it arrived on a truck in Providence on Wednesday.

Capt. David S. Neill, state police detective commander, said it was the largest confiscation the state police have made in a quarter-century. He estimated the street price of the drug at between $1,000 and $3,000 a pound and said that although it was shipped from Laredo, Texas, there is strong evidence the marijuana originated in Mexico.

“Somebody’s out a lot of money,” he said at a news conference at state police headquarters.

Spread out on tables to one side as he spoke were 69 plastic-wrapped bales of compressed marijuana and several rusty brake rotors.

In announcing the operation, Neill was joined by members of the High Intensity Drug Trafficking Area Task Force (HIDTA), composed of members of the state, Providence, Pawtucket, North Providence, Warwick and Central Falls police, agents of the federal Bureau of Alcohol, Tobacco and Firearms, the Bureau of Immigration and Customs Enforcement and at least one member of the Rhode Island National Guard.

Neill said HIDTA officers watched a tractor-trailer being unloaded at K&C Auto Reconditioning, 39 Huldah St., in the Olneyville section of Providence. When they approached to question the driver, he said, the man who had signed for the delivery slipped away and is still being sought. He said the officers brought along Axel, a state police K-9 dog, which immediately indicated there was marijuana present. He said the police then obtained a search warrant for the truck.

He said a search disclosed that several plastic shipping containers had a top layer of brake rotors concealing the marijuana packages. He said the nature of the camouflage indicated “a sophisticated narcotics trafficking organization.”

Neill said the tractor-trailer belonged to R&L Carrier of Wilmington, Ohio. He replied “No comment” when asked whether the police suspect either the truck owner or the car reconditioning company knew what was being shipped.

He said the marijuana had been compressed by a trash compacting machine or a similar device. He said it is believed that the marijuana originated from different areas, and had been squeezed into thin wafers so that it could be concealed within truck walls and other hiding places before the cargo destined for Rhode Island was assembled.

tmorgan@projo.com