Mount Vernon Mayor Richard Thomas is defending himself against new accusations that claim the firing of Public Safety Commissioner Bob Kelly was political retribution.

News 12 obtained documents that suggest Kelly was fired after he refused to rehire the mayor's brother back to the fire department.

Mayor Thomas insists he knew nothing about a secret plan being hatched inside Mount Vernon City Hall to reinstate his brother, former firefighter Henry George Thomas, to the force.

Henry George Thomas, a 13-year veteran, abruptly resigned his position as firefighter and union head in January after pleading guilty to selling guns just blocks away from his fire station while he was on duty.

In a series of emails from city officials, in which the mayor's private email address is included, the city's chief attorney, Lawrence Pocari, directs city officials to get Henry George Thomas his old job back.

On March 31, Pocari stated, "Thomas is going to be reinstated as of the date Jan. 7, 2016, and then he's going out on full medical disability. This has to be done as soon as we can."

Kelly heard of the secret plot and wrote a letter to the mayor saying in part, "The ethical lapse in failing to recognize the severity of the offenses committed by Mr. Thomas and the impact his reinstatement would have upon the legitimacy and credibility of city government and its leaders to govern is felonious."

Kelly was fired a week later, just 90 days after Thomas hired him. 

When asked about the email chain, Mayor Thomas told News 12 that he had not seen it.

News 12 reached out to former Commissioner Kelly about the emails, but he declined to comment.