Nearly a year after it was revealed that Prince died of an opioid overdose, news has surfaced that a prescription for oxycodone was written under the name of a friend and not the artist himself, according to The Hollywood Reporter.

Several documents, including affadavits and search warrants, were unsealed today (April 17) in Carver County District Court as the investigation into Prince’s death continues.

According to the warrants, Prince’s Paisley Park compound and his email accounts were searched, along with the cellphone records of his associates, in an attempt to discover where he got the fatal painkiller Fentanyl that killed him. Prince did not own a cell phone.

One affidavit revealed that Michael Todd Schulenberg–the doctor who came to the singer’s house to deliver test results the same morning the musician died on April 21–admitted to authorities that he prescribed oxycodone to Prince on April 15, the same day the star’s plane had to make an emergency landing.

However, Schulenberg said he “put the prescription in Kirk Johnson’s name [Prince’s longtime assistant and bodyguard] for Prince’s privacy.”

Rolling Stone has reported that Johnson’s statements to police have been inconsistent; despite initially claiming he didn’t know Prince had an addiction, he contacted a rehab clinic days earlier.

Additionally, Rolling Stone says the search warrant revealed that painkillers were “hidden throughout [Prince’s] compound, including stashed in vitamin containers.”

NBC News also reported that “some [controlled substances] were in a suitcase labeled with a Prince alias, Peter Bravestrong, along with a page of handwritten lyrics to the 1987 hit ‘U Got the Look.’”

Despite these discoveries, a joint state and federal criminal investigation is still underway to discover the source of the Fentanyl, since Prince was never prescribed that drug.