The legendary singer died on April 21, and more than a month later tests reveal he passed away from a drug overdose. At the beginning of May, the investigation into Prince's death took a turn when the U.S. Attorney's office and Drug Enforcement Administration joined the efforts.

"The U.S. Attorney's Office and DEA are joining the Carver County Sheriff's investigation," a spokesperson for the U.S. Attorney's office told E! News.

"The DEA and U.S. Attorney's Office are able to augment this local investigation with federal resources and expertise about prescription drug diversion. While this remains an ongoing investigation, we will have no further comment."

The two agencies' involvement in the investigation came shortly after the Minneapolis Star Tribune published a report that said the "Purple Rain" crooner was supposed to meet with a California doctor who specializes in addiction. Prince was allegedly suffering from an addiction to pain killers and had representatives reach out to Dr. Howard Kornfeld, a national authority on opioid addiction treatment, because Prince was "dealing with a grave medical emergency," said William Mauzy, an attorney working with the Kornfeld family.

source Enews