A 69-year-old East Hampton man is being held on $50,000 bail after an investigation revealed he had been abusing a girl sexually for more than three years, East Hampton Town police said. Cesar Augusto Diaz-Illescas, who lives on Muir Boulevard, was charged with second-degree sexual conduct against a child less than 11, a felony charge used when there are two or more alleged acts over more than three months. He also was charged with endangering the welfare of a child, a misdemeanor. The girl had been abused between September 2015 and November 2018, Detective Sgt. Dan Toia said. Police became involved when the mother of the child gave them information, he said.According to the complaint, the victim gave police a statement in January. Detective Toia declined to describe the connection between Mr. Diaz-Illescas and the victim.At his arraignment on Tuesday, East Hampton Town Justice Steven Tekulsky set bail at $50,000 cash or $100,000 bond. Mr. Diaz-Illescas is due back in court today.