NEW YORK - Federal prosecutors have announced charges against three men accused of threatening and intimidating women who have accused R&B singer R. Kelly of abuse.

One of the men is suspected of setting fire to a vehicle in Florida.

Authorities say a longtime friend of the indicted singer offered to pay a victim 500-thousand dollars to keep her from co-operating in Kelly's prosecution -- while a manager and adviser of Kelly threatened to release sexually explicit photographs of a woman who sued Kelly.

The Grammy-award winning musician has denied ever abusing anyone and has pleaded not guilty to dozens of state and federal sexual misconduct charges in Illinois, Minnesota and New York.

The charges range from sexual assault to heading a racketeering scheme aimed at supplying Kelly with girls.

Kelly is also accused of having unprotected sex with a girl in 2015 without disclosing he had herpes.

Prosecutors described a third man accused of intimidating witnesses as being related to a former Kelly publicist.

They say 37-year-old Michael Williams of Valdosta, Georgia, travelled to Florida in June and set fire to an S-U-V parked outside a residence where one of Kelly's victims was staying.

Williams also conducted Internet searches for "the detonation properties of fertilizer and diesel fuel, witness intimidation and witness tampering and countries that do not have extradition with the United States.