Investigations into Irv "Gotti" Lorenzo and his brother Christopher widen as the two hip-hop rap mogul brothers, who adopted mobster John Gotti's name and run Murder Inc. records; are now suspected of wielding a two-by-four "embedded with nails," according to one police report. They reportedly bashed Anthony Sylvester on the head repeatedly until he fell unconscious before dumping his body in a vacant lot on East 124th Street near Fifth Avenue on Oct. 20, 1993.

Investigators said the attackers left Sylvester for dead, but the bloodied victim managed to survive the attack an "intervention of God," his mother, Marietta Freeman, 61, would later say to reporters.

Her son remained in a coma for eight months and then spent the next 10 years living in a hospice with round-the-clock assistance until he finally succumbed to his wounds on Oct. 29, 2003.

NYPD investigators recently handed over new witnesses and evidence in the case to the feds, who are weighing going before a grand jury to obtain a murder charge for the Gottis, whose record label, now called The Inc., is home to superstar R&B singer Ashanti and hip-hop rap artist / actor Ja Rule.

Robert Nardoza, a spokesman for Brooklyn U.S. Attorney Roslynn Mauskopf, declined to comment on the probe.

But Gerald Shargel, a lawyer for Chris Gotti, called the allegation "malicious, false and reckless."

Shargel insisted the Gottis never knew Sylvester and, back in 1993, "were just hardworking kids just trying to make it as construction workers."

According to sources, court records and his relatives, Sylvester, then 33, was living on the fringe and had been arrested about a dozen times, mostly for larceny, possessing stolen property and criminal trespass, from 1991 to 1993.

In early October 1993, he was arrested again, this time on a drug-possession charge, and was sentenced to 30 days at Rikers Island.

He was released on Oct. 19, and the following day, was walking on 104th Street near Fifth Avenue when a car pulled up.

Authorities are now probing whether it was the Gottis who jumped out and pulled Sylvester into the lot, where they took the nail-studded board to his head.

Cops theorize Sylvester either owed money to a drug dealer or had stolen narcotics from him.

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