LOS ANGELES-Arrests of U.S. Marshals are unusual and so is insurance covering the risk of incarceration.

But not on a Hollywood movie set, where an unusual production insurance policy will protect a studio in the event that a star of the movie "U.S. Marshals" should wind up in jail.

The actor, Robert Downey Jr., has had several scrapes with the law, stemming from his alleged abuse of heroin and cocaine. As a result, he was considered a high risk for filmmakers, which could lose hundreds of thousands of dollars daily should Mr. Downey get into more trouble while a movie is being made.

"You have to be insurable to be employable and he was ending up being uninsurable," said Donna Smith, president of Entertainment Coalition, a managing general agent that is a joint venture of Aon Group Inc. and CNA Insurance Cos. "So we made a way for him to be insurable to be employable," she said.

The "lock down and incarceration" coverage that Entertainment Coalition created will allow Mr. Downey to work on the Warner Bros. movie.

The MGA and underwriter declined to discuss how the coverage is structured or how it coordinates with any completion bond that may cover the film.

The coverage was underwritten by CNA and placed by entertainment specialist broker Aon/Albert G. Reuben Insurance Services in Los Angeles.

CNA referred calls to Entertainment Coalition, while Warner Bros. declined comment. Shel Bachrach, president in Los Angeles of Aon/Albert G. Reuben, could not be reached for comment.

"U.S. Marshals" is a spinoff of the movie "The Fugitive" and also stars Tommy Lee Jones and Wesley Snipes. It is scheduled for release early next year and is being filmed in Chicago.

Ms. Smith compared the production insurance for Mr. Downey to coverage that was obtained for Courtney Love, the rock star who co-stared in "The People vs. Larry Flynt."

When Ms. Love announced that she had used heroin while pregnant, it made movie-makers nervous that a drug binge might keep her from showing up to work on the filming of "Larry Flynt," Ms. Smith said.

So getting her insured required some "special things to happen," Ms. Smith said.

"I had a production rep on the show with Courtney who hung out with her all day long," Ms. Smith said. Ms. Love was subject to random drug testing during the movie's production.

Mr. Downey will also be required to undergo random drug tests.

His troubles began two years ago with his first arrest, followed by a second arrest a short time later for suspicion of drug possession and trespassing.

In July 1996, he was arrested three times in a single month, the last occurring after he walked away from a drug rehabilitation facility, according to the Associated Press. In November 1996, he was sentenced to three years probation for drug and weapon charges and ordered to remain in a locked rehab facility for three months. He currently is in a court-ordered drug monitoring program.

"There are a few bad girls and boys out there," Ms. Smith said. "But I don't expect this to happen frequently. My motto has always been, 'We will tell you how instead of telling you no.' So we figured out how to get Courtney insured and now we have figured out how to get Robert insured."

The November 1993 death of actor River Phoenix of a drug overdose created insured losses of nearly $6 million for filmmakers. The insurers, two units of CNA Insurance Cos., later sued the actor's estate, charging breach of service agreements and misrepresented medical certificates (BI, July 25, 1994).

One of the movies, "Dark Blood," had to be scrapped after Mr. Phoenix's death, costing CNA International Reinsurance Co. Ltd. an estimated $5.5 million. In the other, "Interview with a Vampire," Mr. Phoenix was replaced by Christian Slater, costing American Casualty Co. an anticipated $185,000.