BREVARD COUNTY, Fla. — Large bales of rubber weighing hundreds of pounds have been washing up on Florida beaches, and now they're showing up in Cape Canaveral.

Now investigators are hoping to solve the mystery of where they're coming from, and believe the source may date back to World War II.

Leo Cross is a wildlife trapper by trade, but these days he's become a collector.

His work involves gathering large rubber bales like one that recently washed up on the beach at Cape Canaveral's Cherie Down Park.

A heads up citizen reported the find to the authorities.

"They're like 300 pounds each," Cross said, adding that by traveling on the Gulf Stream, "they can hitch a ride anywhere, our coast is like a catch all."

But where did the mystery bales come from?

The theory goes back more than 75 years to World War II and the SS Rio Grande, a German blockade runner supply ship, sunk by the U.S. Navy off the coast of Brazil in January 1944.

"Our colleagues in Brazil have found similar bales on their shorelines, and have been able to trace it to the SS Rio Grande," Florida Fish and Wildlife Conservation Commission Marine Debris Coordinator Dr. Jennifer McGee said.

If true, that would mean the bales washing in Florida meandered some 3,000 miles using the Gulf Stream — helped along by storms — over seven decades before washing up on the Space Coast.

Cross is partnering with FWC to haul away the bales and take them to the Commission's lab in St. Augustine.

That's where McGee will get a chance to study them.

"We are going to be looking at the 'hitchhikers' on the bales, like the barnacles and other organisms," she said. "Opportunities of this type of debris are rare and can give us a lot of information on what's been happening in the ocean."

Cross said he was glad to be a key part of the bales new journey.

"Just to be the first people to handle this stuff since possibly the Germans," he said.

Anyone who spots one of the bales is encouraged to contact FWC Marine Debris Management at: MarineDebris@MyFWC.com.