(CNN) Agents from the U.S. Drug Enforcement Administration and local sheriff's deputies were at the Minnesota home of Prince on Tuesday as part of an ongoing investigation into the music legend's death, a law enforcement official told CNN.
The DEA agents were executing a federal search warrant, the source said.
CNN affiliate WCCO reported more than a dozen vehicles were at the house where Prince, 57, died April 21.
"Detectives are revisiting the scene at Paisley Park as a component of a complete investigation. No other information is available," the Carver County Sheriff's Office tweeted.
The search appears to be the latest in the investigation. The Star Tribune of Minneapolis and the Los Angeles Times each reported Tuesday on a search warrant a Carver County detective executed at the office of a doctor who said he twice examined the singer last month.
According to the warrant, Dr. Michael Schulenberg saw Prince on April 7 and April 20. The doctor told the detective he had prescribed medicine for Prince and the prescriptions were supposed to be filled at a Walgreens.
The doctor came to Prince's house on the day of this death to drop off test results and was there when detectives arrived.
Investigators went to Schulenberg's now former office at a medical center in Robbinsdale in Hennepin County on Thursday to seize medical records.
Deborah Cannon with North Memorial Clinic told CNN the doctor's last day was Tuesday. She gave no details as to why he was no longer employed there. The Star Tribune reported Schulenberg is a family practitioner.
CNN called several numbers listed for the doctor and left a request for comment on his voice mail.
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The day before Prince died, his team called an eminent opioid addiction specialist in California seeking urgent help for the singer, William Mauzy, an attorney working for the specialist and his son, said last week.
The specialist, Dr. Howard Kornfeld, couldn't get there immediately so he sent his son, Andrew Kornfeld, on an overnight flight to Minnesota. The goal was for the younger Kornfeld to help evaluate Prince's health and encourage him to enter treatment for pain management and potential addiction issues, Mauzy said.
Andrew Kornfeld called 911, Mauzy said.
The U.S. Attorney's Office and the DEA announced last week they were joining forces with local investigators, led by the sheriff's office in Carver County, to investigate Prince's death.
The county includes the Minneapolis suburb of Chanhassen, where Prince's Paisley Park complex is located.
Officials have yet to publicly comment on what killed Prince. Results of an April 22 autopsy are pending.
According to a law enforcement source, investigators found prescription opioid medication on Prince and at Paisley Park after his death. 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 last week.
Opioids reduce pain by switching off pain receptors in the brain.
They are among the most widely prescribed drugs in the United States, the Centers for Disease Control and Prevention says. Prescription opioids include painkillers such as morphine, oxycodone and hydrocodone, according to the CDC.
Opioids produce an increased pain tolerance and a sense of euphoria. They trigger a craving when the drug is absent.