A decomposed body believed that of a missing Austrian physician who was conducting drug research here was found by searchers yesterday in a wooded section of a park in Montgomery County. County police said the cause of death has not been determined, but that there were no signs of foul play.

Police said the body, found about 11:40 a.m. in the Cabin John Regional Park, was tentatively identified as that of Rudolph W. Platzer, 35, who was studying and working at the armed forces medical school in Bethesda on a one-year grant from the National Science Foundation of Switzerland.

Platzer had been missing since setting out on the morning of May 19 to pedal his bicycle the half mile from his home in the Maplewood Manor section to the medical school on the grounds of the Bethesda Naval Hospital.

Dr. Lewis Aronow, chairman of the pharmacology department at the school, said Platzer was interested in computer simulation of the process by which drugs are distributed in the body, and came to the medical school because of its reputation in that area.

Aronow said that Platzer had high personal standards, and "everybody knew he was a little depressed about the way work was going."

"It was not as successful as he had hoped," Aronow said.

Police said no formal identification of the body or official determination of cause of death could be given until an autopsy can be performed.

Until yesterday, the only clue to Platzer's disappearance had been his bicycle, found Tuesday chained to a fence near a parking lot in the park where the body was found yesterday. The site is four miles from his home and in the opposite direction from the medical school, known formally as the Uniformed Services University of the Health Sciences.

Aronow was part of a group of friends, students, coworkers and associates from the school who assembled at 10 a.m. yesterday to search again for Platzer in the densely wooded area where the bicycle was found and where a previous search by police and dogs had turned up no clues.

Aronow said the body was found about 500 yards from where the bicycle was found. He said clothing and identification found on the body suggested it was Platzer's.

Platzer was wearing tan slacks and a green pullover when last seen.

Montgomery police Detective Lee Dievendorf said the clothing on the body found yesterday matched that worn by Platzer. He said Platzer's driver's license was found on the body. A briefcase Platzer had carried was also reportedly found. But Dievendorf described the body as badly decomposed, and said it could not be recognized by sight.

After the discovery, made about 35 feet from Goose Neck Loop Trail, Aronow said searchers called Maryland National Capital Park police, who have primary jurisdiction in the regional park.

Platzer's wife could not be reached yesterday for comment. Platzer's wife had told police that her husband had not shown any signs of severe depression.

The night before he disappeared, the couple had dined with friends, and the pharmacologist had reportedly appeared to be in good spirits.