Pittsburgh's Office of Municipal Investigations is looking into police Chief Cameron McLay's Democratic National Convention speech last week.
WTAE-TV reports OMI has confirmed the probe, but not released details. The agency investigates allegations of misconduct by city employees and can make non-binding recommendations for discipline.
The city's police union has expressed unhappiness with the speech, saying police aren't supposed to make political statements in uniform or otherwise engage in politics.
McLay has defended the speech, saying he avoided endorsing any political candidate or viewpoint and, rather, spoke about the need for police to improve their relations with citizens.
The union is also unhappy because the DNC provided a platform for the families of those killed by police to speak, but not for the families of recently slain officers.