A Montgomery County Circuit judge ordered the conditional return yesterday of 17 research monkeys seized last week at a Silver Spring medical laboratory that may have violated Maryland's animal cruelty law.

Assistant State's Attorney Joseph Fitzpatrick had argued that it was necessary to keep the monkeys in the custody of the state for "continued evaluation" and investigative purposes, likening the situation to a child abuse case. But Harvey Steinberg, one of four attorneys representing the Institute for Behavioral Research, argued that their continued retention was unnecessary and harmful to the lab's research.

Judge David L. Cahoon apparently agreed, ordering that the monkeys be returned on the condition that "agents of the Montgomery police and the state's attorney's office" be allowed to "examine, inspect and observe" the monkeys at the lab while considering possible criminal charges. That release was expected to take place within the next few days.

Montgomery County police raided the lab on Sept. 11 after obtaining a search and seizure warrant. Although they confiscated papers, documents, and other physical evidence as well as the monkeys, they have not brought any charges.

Attorneys for the lab, which received $160,000 in funds from the National Institutes of Health this year for its neurological research, petitioned the court this week to argue that there was no further need to keep the animals and records in police possession.

"This research is of great benefit to human beings," said Steinberg, who produced what he said was evidence that the persons charged with the animals' care by police were not adequately trained to handle research monkeys.

Since their seizure, the monkeys have been kept in the basement of a Montgomery County home, according to Montgomery Detective Sgt. Richard Swain. The primates have been examined by three so-called experts of veterinary medicine and primate research in the course of the criminal investigation.

Fitzpatrick argued that the monkeys should not be released because of what he called "squalid" conditions at the lab. However, Judge Cahoon said that U.S. Department of Agriculture officials made an unnannounced inspection of the lab on Thursday and found no deficiencies. His order was also made on the condition that lab conditions do not deteriorate.

Both sides presented photographs in support of their arguments. Fitzpatrick displayed pictures of conditions at the Institute for Behavioral Research taken prior to the raid, while Steinberg produced photos taken by Dr. Edward Taub, the lab's principal investigator, who visited the home where the monkeys are being kept.

One of Taub's photographs showed bare light bulbs which he said might injure the monkeys themselves if they escaped their handlers. But when shown Fitzpatrick's pictures, Taub admitted that there are bare light bulbs in his lab as well.