LOS ANGELES -- Hotel heir Conrad Hilton has been ordered into substance abuse treatment after failing drug tests and violating his probation.

City News Service says a Los Angeles judge on Tuesday ordered Hilton into a residential treatment program for at least 90 days. The judge rejected a request by authorities to put Hilton behind bars for 60 days.

The 21-year-old was sentenced to probation and community service last year after pleading guilty to disrupting a British Airways flight.

Authorities say he violated probation by trespassing, failing drug tests, failing to complete three treatment programs and travelling out of California without permission from his probation officer.