Officials in Mount Vernon Wednesday called for an investigation into the mayor's firing of the city's public safety commissioner, after just months on the job.

City Councilman Andrew Wallace, one of Mayor Richard Thomas' chief political foes, insinuated that the mayor had an ulterior motive when he sacked Bob Kelly after just 90 days on the job.

The mayor has been vague about his justification for the over-the-weekend firing, but Wallace and other opponents have publicly speculated that it may have been in retaliation. They claim Kelly refused to sign off on a secret plan by Thomas' top legal adviser to re-hire his brother, Henry George Thomas.

The mayor's brother quit the fire department in January after pleading guilty to selling guns while he was on duty. 

News 12 obtained confidential emails written by the city attorney ordering that Henry George Thomas be reinstated with back pay -- and then immediately put on disability.

The mayor insisted this week that he had a reason for firing Kelly other than retaliation. When asked whether it would be in the best interest of taxpayers to reinstate his brother, Thomas said the issue was complicated.

Wallace, the mayor's biggest opponent in City Council, apparently agreed with Thomas on that point.

"I don't think that's a question for myself or the Council," Wallace said. "That's a question I think you should ask of the unions."

But a fire union official told News 12 that the Henry George Thomas issue is not a union issue at all and refused to comment further.