The officer who busted Meek Mill might be one of Philadelphia's most corrupt cops ... this according to the Philadelphia District Attorney's Office.
Officer Reginald Graham -- the guy who played a pivotal role in Meek's 2007 arrest for gun and drug charges -- is 1 of 29 current and former cops the D.A. has placed on a "Do not call" list ... warning prosecutors to keep them off their witness stands following allegations of misconduct.
The list -- first obtained by the Philadelphia Inquirer -- states Graham was "investigated by federal authorities for several alleged acts of corruption." Graham was the only witness in Meek's 2008 trial.
Meek's attorney, Joe Tacopina, said "The release of the so-called 'Do Not Testify' list supports everything in the motions filed by Mill and others wrongfully arrested by Officer Graham for post-conviction relief."
Meek, 19 at the time of his arrest, was sentenced to 10 years probation. He was sentenced back in November to 2 to 4 years in prison for violating probation.