FILE - This Friday, Dec. 2, 2016 file photo shows the headquarters of Europol in The Hague, Netherlands. A massive law-enforcement effort across Europe has resulted in the seizure of 24 tons of raw steroid powder and closure of nine underground labs…
FILE - The headquarters of Europol is seen in the Netherlands, Dec. 2, 2016.

A massive continent-wide police operation has netted 24 tons of anabolic steroid powder and 234 arrests across Europe. 

It also resulted in the closure of nine underground labs that produced performance-enhancing drugs and the dismantling of 17 organized-crime groups.

The operation involved 33 countries, including 23 EU nations, the European police agency, Europol, and the World Anti-Doping Agency  (WADA). 

"This is the sort of multi-party collaboration that produces real results and can make a significant impact on the availability of counterfeit and illegal drugs used by some athletes globally,'' WADA intelligence director Gunther Younger said.

Europol said the operation, co-led by law enforcement officials from Italy and Greece, was the largest of its kind.

International law enforcement agencies have recently been taking a closer look at the use of performance enhancing drugs used by athletes. 

Last year,  the U.S. Justice Department charged Russian military intelligence officers in a wide-ranging case that included WADA and the football federation, FIFA.