Dr Michael Schulenberg who saw Prince in the days before he died had prescribed oxycodone under the name of Prince's friend, Kirk Johnson, to protect the musician's privacy, according to an affidavit unsealed on Monday.
The documents show authorities searched Prince's Paisley Park estate, cellphone records of Prince's associates, and Prince's email accounts to try to determine how he got the fentanyl, a synthetic opioid drug 50 times more powerful than heroin.
Dr Schulenberg's attorney, Amy Conners, disputed that. She said in a statement that Dr Schulenberg "never directly prescribed opioids to Prince, nor did he ever prescribe opioids to any other person with the intent that they would be given to Prince".
F Clayton Tyler, Mr Johnson's attorney, released a statement saying that after reviewing the documents, "we believe that it is clear that Kirk Johnson did not secure nor supply the drugs which caused Prince's death".
Prince was 57 when he was found alone and unresponsive in an elevator at his Paisley Park home April 21.