Bolivian prosecutors say two members of an alleged extortion ring that targeted American businessman Jacob Ostreicher have pleaded guilty and are cooperating in hopes of serving less jail time.

The two are lower-ranking officials among 15 people arrested for allegedly trying to shake down Ostreicher. One was assistant to the judicial director of the Interior Ministry.

The New York businessman was arrested on suspicion of money laundering in 2011 while trying to salvage a rice-growing venture and jailed for 18 months without charge until the actor Sean Penn intervened and won him house arrest.

Ostreicher says officials conspired to keep him jailed so they could sell 18,000 metric tons of rice confiscated from him and extort him.

He cannot leave Bolivia until his case is resolved.