The Purple Rain singer's family members launched civil action in 2018, claiming a doctor and pharmacist at Trinity Medical Center in Moline, Illinois, and two Minnesota-based pharmacists from chain store Walgreens contributed to the superstar's death by failing to provide him with reasonable care.

In the documents, the heirs claimed a prescription drug overdose Prince had suffered a week before his April, 2016 death was not diagnosed in a timely manner by staff at Trinity Medical Center, after he became unresponsive during a flight, forcing pilots to make an emergency landing in Moline to allow him to seek medical attention.

The suit suggested that had professionals given Prince appropriate counselling, he may not have died from an accidental overdose of powerful painkiller fentanyl just six days later.

The plaintiffs also took issue with pharmacists at two Walgreens branches in Minnesota for "dispensing prescription medications not valid for a legitimate medical purpose", after the pain pills were prescribed to Prince's bodyguard and assistant Kirk Johnson, on behalf of the musician.

Both claims were quietly dismissed in recent months, indicating a private settlement may have been reached, reports The Associated Press.

Representatives for the late star's family have declined to comment on the news or the reasons for the apparent settlements.

Prince was just 57 when he passed away at his Paisley Park compound in his native Minnesota on 21 April, 2016.

No criminal charges were filed by authorities in the wake of the star's death.