The NFL will conduct a full investigation of allegations that Denver Broncos quarterback Peyton Manning received human growth hormone, according to the Associated Press.

The investigation currently doesn’t have a timetable for completion, but it is not expected to start until after the Broncos play the Carolina Panthers in Super Bowl 50 on Feb. 7.

The allegations arose after Al Jazeera reported that Manning’s wife had received shipments of HGH from an Indianapolis anti-aging clinic.

The report also pointed to drug use by several other NFL players, including Pittsburgh Steelers linebacker James Harrison and Green Bay Packers linebacker Clay Matthews.

Charles Sly, a former pharmacy intern in Indiana who unknowingly spoke to Al Jazeera investigators, recanted his claims about professional athletes and drug use.

Manning has been adamant in denying claims that he took performance-enhancing drugs.