Aretha Franklin's Assets Stolen Before Late Singer's Death, Police Investigating

Aretha Franklin's riches weren't getting much R-E-S-P-E-C-T, allegedly, before she died last August -- cops are on the hunt for someone who stole from her.

According to legal docs, obtained by TMZ, police in Michigan are conducting an investigation into the theft of Aretha's assets before she died.

Law enforcement sources tell us the criminal probe involves someone inappropriately using her funds. We're told a report was filed last June, but it's unclear exactly how much money's gone missing.

As you know ... Aretha's finances have been under the microscope following her death. The IRS is hounding her estate, claiming she owes more than $6.3 mil in back taxes. And, she's being dogged over legal bills.

We're guessing this isn't what Aretha had in mind when she famously sang, "I'm about to give you all of my money."