Chris 'Birdman' Andersen -- I'm the REAL Victim in Extortion Plot

NBA star Chris Andersen -- aka The Birdman -- claims he's NOT guilty of any Internet crime involving children ... claiming he's the victim in an extortion plot involving a 21-year-old woman.

After authorities in Colorado searched the Denver Nuggets player's home and seized property, Andersen's lawyer released a statement ... insisting he was set up by a scorned woman.

Andersen's lawyer explains, "A female fan in 2010 mailed Mr. Andersen multiple letters and included several photos in which she was scantily clad."

"Chris and this woman communicated with each other and in 2011, this woman, who represented herself as 21 years of age, flew to Colorado, showing her required identification. After leaving Colorado, she became upset at his lack of interest. In 2012, she threatened to retaliate if he did not provide financial remuneration. "

Andersen's lawyer claims someone purporting to be the woman's mother followed up with an email that read "I want him to pay for everything on her Amazon wish list, 5K for her bedding stuff and her Victoria's Secret wish list."

The statement continues, "The media has been speculating that he's a suspect and not a victim in a criminal investigation. Mr. Andersen has been fully cooperative with the authorities. The investigation is expected to take three weeks. We're confident it will show that Chris did not engage in any criminal conduct."

For the record -- Andersen has neither been arrested nor charged with a crime.