Irv "Gotti" Lorenzo and his brother Chris are under federal investigation for beating a Manhattan drug dealer to death.

According to a police report, on October 20, 1993, the Gottis beat Anthony Sylvester with a two-by-four punctuated with nails until he fell unconscious. Then the Gotti brothers allegedly dumped their half-dead victim in a vacant lot on East 124th Street and 5th Avenue in Harlem.

Investigators said the assailants left the victim for dead, but the badly beaten Sylvester miraculously survived the assault. Sylvester remained in a coma for eight months and then spent the following 10 years living in a hosp!ce with constant assistance until he died from his wounds on October 29, 2003. NYPD investigators recently provided new witnesses and evidence for the case to the feds; who are considering going before a grand jury to get a murder charge against the music mogul brothers.

Robert Nardoza, a spokesman for Brooklyn U.S. Attorney Roslynn Mauskopf, wouldn't comment on the probe. However, Gerald Shargel, one of Chris' lawyers, called the accusation "malicious, false, and reckless." Shargel claims that the Gottis never knew Sylvester and that they "were just hardworking kids just trying to make it as construction workers" back in 1993. According to sources, court records and Sylvester's relatives, the then 33-year-old had been arrested at least a dozen times for violations like larceny, possession of stolen property and criminal trespass, from 1991 to 1993.

In early October 1993, Sylvester was arrested on a drug possession charge and sentenced to 30 days at Rikers Island. Reports say that he was released on October 19 and was walking on 104th Street near 5th avenue the next day when a car pulled up. Authorities are now investigating to determine whether the Gottis got out of the car and took Sylvester into the lot where he was fatally beaten. Cops believe that Sylvester either owed money to or had stolen narcotics from another drug dealer.

"It looks like they tortured him, hitting him on the head and probably demanding with each blow to know where their money or product was," an investigative source said.