Police say a tipster may have helped them crack a nut-nabbing syndicate.

Two people were arrested early Monday after about $400,000 worth of stolen almonds was discovered in a Sacramento warehouse, a stash investigators say may be linked to a rash of nut thefts from orchards across California's Central Valley.

The tipster had read about the thefts and called police Sunday after seeing workers transporting boxes from various nut processors between a rental truck and the warehouse, Merced County Sheriff's Detective Vince Gallagher said.

Police arrested Sukhwinder Singh Grewal, 41, and Amrik Singh, 27. Grewal is the owner of Sona Spice Imports, a Sacramento-based importer and wholesaler of goods from India. Gallagher said both are expected to face charges of receiving and possessing stolen property.

Investigators suspect that the almonds in the warehouse were stolen from Central Valley orchards, and they are examining whether the importer was selling them to stores, Gallagher said.

As prices for almonds have risen with demand, a growing black market has emboldened thieves to cut holes in fences, sneak into distribution centers and drive off with truckloads of nuts.

Growers in California's Central Valley produce about 80 percent of the world's almonds.

The discovery at the warehouse was a rare break in a series of thefts that has cost California farmers at least $1.5 million in stolen almonds this year, according to the Agricultural Crime Technology Information and Operations Network. The network is a coalition of agricultural commissioners offices, district attorney offices and sheriff's departments in the Central Valley.

Detectives are working to stop the thefts and crack what may be a syndicate, police Sgt. Terrell Marshall said.