(CNN) Authorities are trying to figure out how bricks of cocaine worth more than $1 million wound up in banana shipments delivered to three grocery stores in Washington state.

The drugs were found Sunday at Safeway stores in Woodinville, Bellingham and Federal Way.

Produce workers at the Woodinville store were putting the bananas out on the sales floor when they saw something strange, said Sgt. Ryan Abbott with the King County Sheriff's Office.

"One of the boxes had brown paper in it, which caught their attention and then they looked further and found these bricks," Abbott said. "They called the police and we went out there and it ended up being 22 kilos of cocaine with a street value of $550,000."

That's almost 50 pounds of cocaine.

Read More