Metro Transit officials in the Twin Cities have confirmed there is a major investigation of employees at its Hiawatha light-rail maintenance shop in south Minneapolis, KSTP reports.

A source told the television station the five-month probe, which began in December, includes allegations that multiple managers and hourly employees exchanged pills and firearms for more lucrative overtime shifts.

Watch KSTP's story below:

A Metro Transit spokesman told the Star Tribune that the investigation, which is being conducted by an outside agency, is expected to wrap up soon.

So far, no disciplinary action has taken place.