It could also add to the tensions within Mr Cardoso's fractious coalition (which almost came to blows this week over the choice of a new chiefof the federalpolice).
The former mayor, policechief and a village trustee all pleaded guilty last year to federal charges of trafficking highly sought AK-47-style pistols to Mexican cartels.
The federal home ministry is also considering the position of the city's policechief, Neeraj Kumar, said a person with direct knowledge of the matter who asked not to be named.