Roman Leimer, the Montgomery County man who at first was believed to have died in a fiery truck crash last month in Virginia, was indicted yesterday on a charge of arson. A warrant also was issued for the arrest of Leimer, who now is listed as missing.

Leimer, 39, an Exxon gasoline tank-truck driver and wine importer, was accused of felony arson in the indictment returned by a grand jury in Warren County (Front Royal), Va. The crime is punishable by up to 10 years in prison. Bond was set at $100,000.

Leimer's 8,900-gallon Exxon tanker was found ablaze on I-66 near Front Royal in the early morning hours of Jan. 13. The Austrian-born Leimer was presumed dead until a Smithsonian Institution scientist, called into the case by Virginia authorities, determined two weeks later that the remains found at the scene were not human, but those of a pig.

Warren County commonwealth's attorney David Crump, who is coordinating the investigation of Leimer's disappearance, said yesterday that Virginia authorities have talked to a reliable witness who reported seeing Leimer last week in Maryland.

Officials said Leimer's wife, Antonia, who is living at the family's home in Burtonsville with the couple's three children, has refused to take a polygraph test and has declined to be interviewed by police or reporters.

Sources close to the investigation also disclosed yesterday that Mrs. Leimer filed an insurance claim after the crash, and that she has been trying for several weeks to get Virginia authorities to issue a death certificate.

Crump yesterday asked Virginia authorities to begin an investigation of possible insurance fraud. Maryland authorities have not yet become involved in the case.

Since the crash more than a month ago, Leimer's disappearance has been a growing tale of intrigue, beginning with the discovery that chunks of charred flesh and bone found in the truck's cab were actually three ham bones.

Suspicions grew further when Virginia state police trooper Ronkeith Kirtley reported having seen Leimer's tanker parked on the side of the road about 15 minutes before the fire broke out. Kirtley said Leimer was standing near the truck smoking a cigarette, and told the trooper he was taking a rest because he was drowsy.

About a half-mile behind the tanker, Kirtley had stopped to talk to the driver of a small, blue car parked on the shoulder. The driver was a blond woman with a German accent. Police have a composite drawing of the woman but have not released it.

The tanker fire occurred at a time when Leimer was on the brink of bankrupcy, threatened by mounting debts and lawsuits for overdue loans to his fledgling wine business, Romax, Inc., in Jessup, Md.

According to sources close to the investigation, the Virginia state police have gathered evidence showing that Leimer's 45-foot tanker was deliberately put off the road and set on fire at the base of a 35-foot embankment.

Sources said Virginia investigators have evidence showing that Leimer purposely set the truck on fire after easing it off the road and down the embankment. The truck, valued at $100,000, was standing upright when firefighters arrived on the scene.

Police recovered a man's wristwatch near the truck. And a tow truck operator and a rescue worker said they saw a pair of low-cut men's shoes at the top of the hill. Police confirmed this week that two empty bottles of St. Pauli Girl beer (imported from Germany) were found at the side of the road where the tanker was set on fire. No fingerprints were found on the bottles, police said.

A Wheaton travel agency, Foreign Travel Inc., reported to police that Leimer had reserved four airplane tickets to Europe on Jan. 22, three days after his disappearance. But investigators said the tickets were never picked up.