That Ken Griffey Jr. Mariners uniform or Matt Hasselbeck Seahawks jersey you bought online our outside the ballfield may not be the real deal after all.

Seattle police have broken up a counterfeit athletic jersey operation that likely sold hundreds of fake jerseys to customers.

And unless someone told you they're not the genuine article -- uniforms that are National Football League-approved or have Major League Baseball's stamp of approval -- you probably wouldn't know any better.

The three-month long investigation began on October 20th, when a Vice Unit detective took in a complaint that an individual was selling counterfeit NFL Jerseys on Craigslist.

Investigators believed the same guy was also selling counterfeit jerseys around the stadiums.

So detectives did a little legwork -- contacting an NFL representative who offered to help with the investigation. Police used the league representative's expertise to confirm the jerseys were fake, as a detective posed as a buyer and purchased a jersey.

A few weeks later, in early December, police arrested the suspect selling the jersey.

He cooperated with detectives and provided information that another man was the actual source of the counterfeit jerseys.

Detectives then began an investigation of that suspect, which included undercover buys of the jerseys, surveillance of the suspect and warrants to establish the suspect's ownership of a website dedicated to selling the counterfeit jerseys.

Yesterday, detectives and officers arrested the suspect in north Seattle.

After serving a search warrant on the suspect's residence. Over 900 counterfeit jerseys were seized -- totalling about $90,000 in value.

A number of these jerseys were New Orleans Saints counterfeits with Reggie Bush's name and number, presumably trying to capitalize on their appearance in Sunday's Super Bowl. Several others included a replica of Gaylord Perry's Mariners uniform and Ken Griffey Jr.'s uniform.

Police say the suspect will be charged with counterfeiting.