Prince George's County police donned scuba gear yesterday and searched a swampy area in Croom for clues to the disappearance of 20-year-old Kimberly Christine Mileo.

Police said the second day of searching produced no new information on the Kettering woman, who was last seen early last Thursday.

Police, who say they suspect foul play in the disappearance, said friends of Mileo have offered a $1,000 reward for information on her whereabouts. Police said anyone with information should call their Crime Solvers unit at 735-1111.

Mileo, a graduate of Frederick Douglass High School, lives with her father, who is a car salesman, and stepmother in a town house at 49 Watkins Park Dr.

Louise Mileo said last night her stepdaughter had a day off last Wednesday from her job at Bloomingdale's at White Flint Mall and left home at about 10 a.m. and went swimming with a girlfriend. She said she planned to visit her boyfriend later that day.

Police said Mileo's boyfriend, Dana Hudson, said she left his residence at 16411 Mount Calvert Rd. in Croom about 2:30 a.m. Thursday.

Hudson said he and some friends went looking for her after Mileo's stepmother called him at work Thursday and said she had not come home. Hudson said he and a friend drove to Ocean City, Md., on Friday to look for her because the couple had planned a trip there last weekend.

Later that night, Hudson said one of his friends found Mileo's Chevrolet Vega parked along a wooded area in the 16000 block of Croom Road, which police said is about 10 miles south of Hudson's residence and in the opposite direction of Mileo's home.

Police said that when they inspected the car on Saturday, they found Mileo's purse, wallet and a rubber sandal inside.

In a telephone interview yesterday, Hudson, 24, said Mileo was upset by a discussion they had just before she left his house, but he said he did not believe she would have wandered off in the wrong direction that late at night.

"I had hoped to see her the next day," Hudson said. "I knew something was wrong" when her stepmother called.

Hudson said that over the weekend he allowed police to administer a polygraph test to him, but he said the results were incorrect.

"Something's wrong with that machine," he said, adding he would not go back for another test. Police would not comment on the polygraph.

On Monday, homicide detectives and 80 volunteer police, firefighters and neighbors searched the wooded area where Mileo's car was found. Yesterday, after divers from the special operations division were unsuccessful, police made plans to dispatch a helicopter carrying a heat-sensitive device over the wooded area.