The Drug Enforcement Agency and U.S. Attorney's Office officially joined the investigation into Prince's death Wednesday, hours after an attorney for a California physician revealed representatives for the singer had sought help for his reliance on painkillers.

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

The Carver County Sheriff's Office requested help from the DEA last week after prescription painkillers were found in Prince's possession after his death, NBC reported. Authorities did not elaborate on the medications.

Investigators were working to determine whether prescription painkillers might have played a role in the musician's death. Results of an autopsy and toxicology report are expected in the coming weeks.

The DEA was expected to focus on identifying the prescription medications found on Prince and determining where they came from.

Attorney William Mauzy confirmed on Wednesday that representatives for Prince contacted addiction treatment specialist Dr. Howard Kornfeld in an attempt to help him kick a painkiller habit.

"Dr. Kornfeld felt that his mission was a lifesaving mission, so certainly he felt it to be urgent," Mauzy said.

Kornfeld was unable to immediately leave his work in California, so he sent his son, Andrew Kornfeld, to explain the treatment process to Prince in Minnesota. When he arrived the morning after representatives asked for Kornfeld's help, Prince was missing. He was found unconscious a few minutes later and Andrew Kornfeld called 911.

Prince was 57 years old.