DUBLIN, California (CNN) -- Heidi Fleiss, dubbed the "Hollywood Madam" and convicted of running a high-priced prostitution ring serving Tinseltown's rich and famous, was released from a federal prison Thursday.

Fleiss, who served 20 months of a 37-month sentence, was released to a halfway house to finish the remainder, according to Dominic Gutierrez, a spokesman for the federal prison in Dublin, about 30 miles east of San Francisco.

In a case that grabbed sensational national headlines, Fleiss was arrested in 1995 after an undercover sting operation. Just who was on her client list became a hot topic of Hollywood speculation. The most high-profile man identified as a client was actor Charlie Sheen.

Fleiss was convicted on federal charges of conspiracy, tax evasion and money laundering. As part of a plea bargain, she's also serving a concurrent state sentence of 18 months for attempted pandering, a charge to which she pleaded guilty in 1997.

Reuters contributed to this report.