The body of a man discovered early Tuesday in the smoldering ruins of an Arlington motor home was identified by police yesterday as Frank E. Bilgere, 36, of 8940 Tackett Ave. in Manassas.

An autopsy conducted yesterday determined that Bilgere died of carbon monoxide poisoning, a result of smoke inhalation, according to Arlington County police spokesman Tom Bell.

Although fire officials said the cause of the blaze is still being investigated, police believe the death was accidental, Bell said. "We have no reason to suspect any foul play."

What remains a mystery to authorities and to Bilgere's family is why he was in the vehicle, a 1972 Dodge motor home that was owned by his half-brother, Jim Cox of 3817 S. Ninth St.

Police and fire officials said they received several calls from residents of the area, reporting the vehicle was burning about 4:42 a.m. Tuesday. When they arrived, they found the motor home, parked in a grassy lot, "engulfed in quite a lot of flames," according to Deputy Fire Marshal Henry Dayton.

The fire was extinguished in 10 to 15 minutes, Dayton said. He said firefighters discovered Bilgere's badly burned body as they raked through the wreckage.

Frank Bilgere's father, Erwin Bilgere of Arlington, said he last saw his son late Monday. "He was at my house until 11 p.m.," when he left, saying he was going to a nearby delicatessen, the father said. "We thought he was coming right back."

"Nobody can understand why he went up there," Erwin Bilgere added. The only explanation the father could offer was that his son, who had an early appointment the next day, decided to sleep in the motor home rather than risk waking his parents, whom he was visiting, when he got up.

Police said family members told them that Frank Bilgere occasionally slept in the motor home, that he was fond of reading and smoking cigars and that he sometimes read by candlelight in the vehicle.

Erwin Bilgere said his son, who was married and had a 15-year-old son, did maintenance work for Hair Pair, a chain of beauty salons in the Washington area.

Fire officials said the blaze destroyed the motor home and damaged an MG convertible nearby, causing about $20,000 in damage.