ESPN sideline reporter Erin Andrews is vowing legal action against an unknown video voyeur after grainy footage showing the sports pro walking around a hotel room naked leaked online last week.

Searches for the video surged to the top of the Google Hot Trends list last weekend — as pervs “sports fanatics” risk violating laws and downloading computer viruses to get to the video.

The 31-year-old blonde, who was christened “America’s Sexiest Sportscaster” by Playboy Magazine in 2008, says she was filmed through the door’s peephole without her knowledge.

“While alone in the privacy of her hotel room, Erin Andrews was surreptitiously videotaped without her knowledge or consent. She was the victim of a crime and is taking action to protect herself and help ensure that others are not similarly violated in the future,” Erin’s attorney, Marshall B. Grossman, said in a statement Tuesday.

“Although the perpetrator or perpetrators of this criminal act have not yet been identified, when they are identified she intends to bring both civil and criminal charges against them and against anyone who has published the material. We request respect of Erin’s privacy at this time, while she and her representatives are working with the authorities.”