The California model, who appeared in 2003 movie Playboy: The Ultimate Playmate Search, was vacationing with boyfriend Kevin Kylm in Florida when her body was found.
She had been burned, killed and dumped. Police had to use dental records to identify her.
Kylm told police he and Sladewski were separated at a club - hours before her body was found.
Klym's attorney tells the Miami Herald newspaper, "He's fully co-operating in the investigation. He's done everything he can do to help locate her prior to the discovery of the death... He's devastated and traumatised. He has no involvement whatsoever."
Sladewski's parents have appeared on U.S. TV pleading with anyone who has information to help them locate the model's killer and find out why her death was so awful.