'Nothing Compare 2 U' singer has also accused comedian of spiking her
The late musician's cause of death is still weeks away from being revealed
Police are looking into possibility that star died from an overdose of prescription drugs
Prince once called Wonder a 'role model' and 'inspiration'
Claims from opioid addiction specialist come as police investigate whether singer died from an overdose
Pair worked together in Prince's final years
'Purple Rain' singer even invited Brown to his Paisley Park home
Singer's diet changed and he was losing weight, says Ray Roberts
Dan Phillips announced his exit on Facebook