The U.S. Attorney's Office and the Drug Enforcement Agency announced Wednesday they're joining forces with local investigators led by the sheriff's office in Carver County. The county includes the Minneapolis suburb of Chanhassen, where Prince's Paisley Park complex is located and where he died.
They will provide "federal resources and expertise about prescription drug diversion," according to a statement issued by federal prosecutors in Minneapolis.
According to a law enforcement source, investigators found prescription opioid medication on Prince
and in his Minnesota home after his death.
So far, investigators haven't found valid prescriptions for the painkillers, law enforcement sources told CNN last week and again Thursday.
Federal investigators will try to determine if people in Prince's inner circle may have helped obtain drugs for him, law enforcement officials familiar with the investigation told CNN.
The DEA has an entire branch devoted to prescription drug abuse, which can involve complicit doctors or pharmacists, patients obtaining multiple prescriptions from a variety of physicians or the purchase of illegally obtained prescription drugs from illicit sources.
Officials have yet to publicly comment on what killed Prince. Results of an April 22 autopsy are still pending.
His issues with addiction
Also Wednesday, we learned that Prince's team sought help from Dr. Howard Kornfeld
, an eminent opioid addiction specialist, the day before the entertainer died. Kornfield sent his son, Andrew, to Minnesota, to prep the singer for a possible trip to California for treatment.
By the time he arrived at Paisley Park on the morning of April 21, it was too late. Andrew Kornfeld ended up calling 911 to report Prince had been found unresponsive.
Since then, a former attorney for two of Prince's dead siblings has come forward with more troubling information. Lawyer Michael B. Padden said the siblings revealed Prince had an addiction to Percocet decades before his sudden death.
Duane Nelson, who died in 2013, was adamant that Prince was in no way just a recreational user, Padden said. The singer started using the drug to help him deal with the rigors of performing, Nelson said. Another half-sibling, Lorna Nelson, confirmed Prince's drug use but was not involved in getting drugs for him, Padden said. She died in 2006.
Adding to the mystery, reports from the Carver County Sheriff's Office revealed that four medical emergency calls
were made from Prince's home between 2013 and the date of his death.
The future of his estate
It's hard to imagine that Prince gave no thought to the fate of his estate, yet no one seems to know what he wanted because they can't find a will.
Prince was worth $300 million, according to various estimates, and his estate is expected to grow as sales of his music continue to explode.
Without a will, under Minnesota law
his estate would go to his sister and his half-siblings. They would control his brand, including Prince's NPG record label, thousands of unreleased songs and the contents of a vault
the musician left behind.
A probate hearing
on Monday concluded with the appointment of a special administrator but no will. Bremer Trust will work on behalf of the heirs of the estate under the direction of the court, a representative said in a statement.
As the search for heirs gets underway, the probate court on Friday authorized the trust to perform genetic testing on a sample of Prince's blood "for any purpose relevant to the administration of the estate." The Midwest Medical Examiner currently has the sample.
Of particular interest to fans is the fate of Prince's vault of unreleased music.
Musicians Paul Peterson and Eric Leeds, both of whom recorded with Prince, told CNN's Stephanie Elam that they've been inside the vault where Prince supposedly stored much of his unpublished music.
About 90% of the music Prince recorded is in the vault and "has never seen the light of day," Leeds said.