Celebrity gossip website TMZ reported that Edis Kayalar, the 26-year-old friend of the former nanny for Crawford's daughter, threatened to release the picture to the media unless he was paid $100,000.
The picture was taken during a game of “cops and robbers” without the knowledge of Crawford, 43, her agent said in a statement.
Documents filed in a federal court state that the nanny took the pictures as a “prank” and that Kayalar, a male model, then stole them from her.
Crawford's husband Rande Gerber paid Kayalar $1,000 (€670) for what he believed was the original photo, the documents stated. But Kayalar contacted him several days later demanding more money, at which point the couple went to the police, who passed the case on to the FBI.
Kayalar was deported from the United States to Germany in September for immigration violation, the media reports stated. People magazine reported he was now in Stuttgart.
On November 1, Kayalar then contacted the couple again, demanding $100,000 and claiming he “had no choice now but to extort the victims for money because they had gotten him deported."
Kayalar now faces up to two years' jail, though the nanny, who was not named, had not been charged, People magazine reported.