DETROIT – Criminal felony warrants have been issued against the Detroit businessman who hired private investigators to follow Mayor Mike Duggan.

Robert Carmack has been charged with four felonies about a month after he drove a giant billboard around Detroit City Hall with video he said proved Duggan was having an affair.

Days later, Duggan held a press conference accusing Carmack of possibly defrauding the city with forged property documents.

Carmack has said he was afraid of Duggan retaliating against him, and now he has been told to turn himself in to authorities.

He's facing three counts of uttering a publishing and one count of obtaining money under false pretenses, officials said.

The charges involve property Carmack was given a deed to 10 years ago and then sold in 2017 for $1 million. City officials said he forged documents to steal the property.

Carmack said in the past that this is a setup. He spoke with Local 4 Defender Kevin Dietz on Wednesday morning.

"We've just learned that there have been four felony warrants signed for your arrest," Kevin said.

"I can't comment at this time," Carmack said. "You'd have to talk to my attorney."

"Does it surprise you that this happened just after you rented the Jumbotron and embarrassed the mayor?" Kevin asked.

"I tell you, my attorney told me not to talk," Carmack said. "He told me to say no comment at this period of time."

"Later, can we talk to your attorney, or will you talk to us after at an appropriate time?" Kevin asked.

"Exactly," Carmack said. "I'll have my attorney call you and so forth and try to move forward with this situation that I'm in."

Carmack's attorney told Local 4 this is a retaliation strike by city officials, saying the property in question has been publicly disputed for years. He said weeks after Carmack exposed the mayor, there are suddenly criminal charges.

Detroit prosecutors recused themselves from the case so a prosecutor from Flint will handle the prosecution, officials said.

Carmack is expected to turn himself in Thursday and be arraigned by video in 36th District Court.