An investigation has revealed that mislabeled pills found at Prince's Paisley Park estate contain fentanyl, according to the Associated Press — two months after an autopsy revealed that the legendary musician died from an overdose of the drug.
The AP, citing an official who spoke on the condition of anonymity, said at least one of the pills of the more nearly two dozen found tested positive for fentanyl, a highly addictive opioid 50 times more powerful than heroin. The counterfeit pills were mislabeled "Watson 385," a stamp that's supposed to indicate pills containing a mix of acetaminophen and hydrocodone.
PHOTOS: Prince through the years
Prince through the years
Prince through the years
Singer Prince performs in a surprise appearance on the "American Idol" television show finale at the Kodak Theater in Hollywood, California in this May 24, 2006 file photo. REUTERS/Chris Pizzello/Files
NEW YORK - FEBRUARY 15: American singer, songwriter, musician and actor Prince performing in NYC at the Bottom Line on February 15, 1980. (Photo by Waring Abbott/Getty Images)
Prince performing in Minneapolis on April 30,1990. (Photo: Frank Micelotta/ImageDirect)
American pop star Prince performing at Wembley, London, 22nd August 1990. (Photo by Graham Wiltshire/Hulton Archive/Getty Images)
PRINCE IN "ROCK IN RIO" CONCERT, BRAZIL 1992. (Photo via Alamy)
American singer-songwriter Prince performs on stage, London, 1993. (Photo by Michael Putland/Getty Images)
The Artist formerly known as Prince performing at Shoreline Amphitheater in Mountain View Calif. on October 10th, 1997. Image By: Tim Mosenfelder/ImageDirect
FOR RELEASE WITH STORY BC-ENTERTAINMENT-PRINCE - The Artist formerly known as Prince seen here in a publicity photograph, July 29. The Artist formerly known as Prince has a new album "Newpower Soul" which was recorded, pressed and distributed by his NPG records label without the assistance of a major industry label.
05/16/00 New York City The Artist Formely Known as Prince reclaims his name 'Prince' and announces public tours at his Paisley Park Studio, during a press conference in New York City. Photo by Evan Agostini/ImageDirect
UNDATED FILE PHOTO: Singer Prince. (Photo by Diane Freed)
LOS ANGELES - FEBRUARY 8: Musical Artist Prince performs at the 46th Annual Grammy Awards held at the Staples Center on February 8, 2004 in Los Angeles, California. (Photo by Frank Micelotta/Getty Images)
Singer Prince, who was presented the Vanguard Award, performs during the 36th NAACP Image Awards at the Dorothy Chandler Pavilion, Los Angeles, March 19, 2005. The award show will be telecast on the Fox televison network in the United States on March 25. REUTERS/Lee Celano ljc/MK
HOLLYWOOD - FEBRUARY 27: Musician Prince arrives at the 77th Annual Academy Awards at the Kodak Theater on February 27, 2005 in Hollywood, California. (Photo by Carlo Allegri/Getty Images)
LOS ANGELES - MARCH 19: Musician Prince performs onstage at the 36th Annual NAACP Image Awards at the Dorothy Chandler Pavilion on March 19, 2005 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)
Milan, ITALY: US singer Prince is pictured during Italian fashion house Gianni Versace show during the Spring/Summer 2007 women's collections, 29 September 2006 in Milan. AFP PHOTO (Photo credit should read STR/AFP/Getty Images)
MIAMI GARDENS, FL - FEBRUARY 04: Musician Prince performs during the 'Pepsi Halftime Show' at Super Bowl XLI between the Indianapolis Colts and the Chicago Bears on February 4, 2007 at Dolphin Stadium in Miami Gardens, Florida. (Photo by Doug Pensinger/Getty Images)
MIAMI - FEBRUARY 01: Musician Prince performs during the Super Bowl XLI Half-Time Press Conference at the Miami Convention Center on February 1, 2007 in Miami, Florida. (Photo by Evan Agostini/Getty Images)
July 7th, 2007 - Minneapolis, MN, USA - The first ten fans in line for an exclusive Prince performance at Macy's downtown received photographs of the iconic Minneapolis funk rocker. Prince performed with his band on the 8th floor at Macy's downtown during an exclusive concert launching his new per
WEST HOLLYWOOD, CA - FEBRUARY 25: Recording artist Prince leaving the 2007 Vanity Fair Oscar Party at Mortons on February 25, 2007 in West Hollywood, California. (Photo by Evan Agostini/Getty Images)
PASADENA, CA - JUNE 01: Singer Prince performs onstage during the 2007 NCLR ALMA Awards held at the Pasadena Civic Auditorium on June 1, 2007 in Pasadena, California. (Photo by Kevin Winter/Getty Images for NCLR)
LOS ANGELES, CA - FEBRUARY 10: Singer Prince on stage at the 50th Annual GRAMMY Awards at the Staples Center on February 10, 2008 in Los Angeles, California. (Photo by Lester Cohen/WireImage)
THE TONIGHT SHOW WITH JAY LENO -- Episode 3737 -- Air Date 03/27/2009 -- Pictured: Musical guest Prince performs during the Mercedes Benz outdoor concert series on March 27, 2009 -- Photo by: Paul Drinkwater/NBCU Photo Bank
US singer Prince performs on October 11, 2009 at the Grand Palais in Paris. Prince has decided to give two extra concerts at the Grand Palais titled 'All Day/All Night' after he discovered the exhibition hall during Karl Lagerfeld's Chanel fashion show. AFP PHOTO BERTRAND GUAY (Photo credit should read BERTRAND GUAY/AFP/Getty Images)
NEW YORK - JUNE 08: Prince attends the Apollo Theater's 75th Anniversary Gala at The Apollo Theater on June 8, 2009 in New York City. (Photo by George Napolitano/FilmMagic)
Prince Tour 2011
US singer and musician Prince (born Prince Rogers Nelson) performs on stage at the Stade de France in Saint-Denis, outside Paris, on June 30, 2011. AFP PHOTO BERTRAND GUAY (Photo credit should read BERTRAND GUAY/AFP/Getty Images)
It's currently not clear how Prince obtained the drugs. The official told the AP that Prince did not have a prescription for any controlled substances in the 12 months before his death. The investigation is ongoing.
Some of the other drugs police found also reportedly contained codeine, and some were not controlled substances. An aspirin bottle found on his estate contained more than 60 pills, the AP reports. Authorities also apparently found ten oxycodone pills in a bottle with someone else's name on it (police are not revealing the name).
Prince was found dead in his home outside of Minneapolis, Minn., on April 21 at the age of 57. His autopsy results were released in June.