MELVILLE, N.Y. - Investigators have found a body hidden in a wall in the Yale University laboratory where a missing graduate student had last been seen, officials said yesterday.

Police believe the remains are those of Annie Le, 24, reported missing Tuesday night, assistant police chief Peter Reichard said at a hastily called news conference last night.

Reichard said the body was found about 5 p.m. in a chase - a vertical space used for ducts, pipes, and wires - in the lab at 10 Amistad St. in New Haven, Conn.

"We are assuming that it is her," said Reichard, who said the investigation into Le's disappearance has been classified a homicide. "We have been in contact with family members of Annie Le and our sympathy goes out to the family."

The president of Yale sent an e-mail message to students last night, announcing that a body had been found in the basement of the university laboratory.

"Our hearts go out to Annie Le's family, fiancé and friends, who must suffer the additional ordeal of waiting for the body to be identified," wrote Richard C. Levin, the Yale president. He added, "Law enforcement officials remain on the scene; this is an active investigation, and we hope it is resolved quickly."

Le, a doctoral student in pharmacology from Placerville, Calif., who had been missing since Tuesday, was to marry Jonathan Widawsky, a Columbia University graduate student from Huntington, N.Y., at Syosset's North Ritz Club on Saturday. The nuptials were canceled on Friday.

The FBI and Connecticut State Police had been searching trash at a Hartford incinerator yesterday for remains of the graduate student.

No one was home yesterday at the Widawsky family home in Huntington. Police have been saying Widawsky, a Columbia University graduate student, is not a suspect in the case and is cooperating.