On stage, Prince was still captivating audiences at recent performances in Australia and California.
He hosted a pop-up party at his Paisley Park studio, and there were few outward signs in his final months that anything was wrong.
But off stage, something was different.
Prince began wanting meals that were easier to digest and was fighting off waves of sore throats and frequent upset stomachs, the musician's personal chef has told The Associated Press.
A law enforcement official said investigators were looking into whether Prince, who was found dead at his home on April 21, died from an overdose and whether a doctor was prescribing him drugs in the weeks beforehand.
The official spoke on condition of anonymity because he was not authorised to speak to the media.
Ray Roberts, who cooked for Prince nearly every day for almost three years, said in an interview that wasn't the man he saw nearly every night, "not even a hint. Not at all".
But Roberts did start noticing changes in Prince's diet - he was eating less and drinking less water, and looked like he was losing weight.
"It felt like he wasn't himself probably the last month or two," Roberts said.
"I think he was just struggling with being sick a lot."
Prince, who didn't eat meat, normally loved foods like roasted beets and minestrone soup.
In recent months, Roberts said, as Prince would have sore throats or seem like he wasn't feeling well for "weeks at a time", he would prefer smoothies and fresh juices to soothe his throat or stomach.
Roberts last saw Prince the evening before the musician was found dead at Paisley Park.
He cooked Prince a roasted red pepper bisque with a kale and spring vegetable salad, but Prince never ate it.
When he returned to the musician's studio home for his memorial service a few days later, Roberts found it in the refrigerator - just as he'd left it.
