Two men have pleaded guilty to charges of secretly taping Michael Jackson.
Michael Jackson recently visited Germany
Jeffrey Borer and Arvel Jett Reeves admitted installing two video recorders on a private jet to tape Mr Jackson and his lawyer at the time, Mark Geragos.
Mr Jackson was flying from Las Vegas to Santa Barbara in November 2003 to face questions over child abuse allegations.
He was found not guilty of child abuse charges in June last year. Borer and Reeves are due to be sentenced in Los Angeles on 12 July.
The pair each pleaded guilty to one count of conspiracy in a federal district court, said Thom Mrozek, a spokesman for the US attorney's office in Los Angeles.
They could be jailed for up to five years.
Prosecutors dismissed two other charges - endeavouring to intercept oral communication and witness tampering.
Borer was the owner of XtraJet, which flew the plane Jackson and Mr Geragos chartered. Reeves owned a company called Executive Aviation, which provided a maintenance service to XtraJet.
According to the plea agreement, Borer instructed Reeves to buy and install the devices. Borer intended "to sell these recordings to the media for a large sum of money", it said.
Reeves bought video and audio equipment and, with an unindicted suspect, secretly installed the equipment in the cabin of the aircraft.
But he was unable to use the remote microphones he had purchased because he did not have the proper connectors, so the two recordings were made without sound.
Meanwhile, a woman has been charged with murder over the death of ex-Jackson Five drummer Johnny Jackson.
Yolanda Davis, 44, was held without bail in Indiana on Monday and could face between 45 and 65 years in prison if convicted.
Mr Jackson was found dead in his home in Gary, Indiana, on Wednesday.
Police detective Tom Decanter Jr said in an affidavit that Ms Davis said she grabbed the knife after Mr Jackson choked and struck her. Police found him later with a stab wound to his chest, the affidavit said.
Mr Jackson replaced the Jackson Five's original drummer in the late 1960s.
The group, fronted by Michael Jackson and including his brothers Tito, Jermaine, Marlon and Jackie, had a string of hits including I Want You Back, ABC and The Love You Save.
It is not clear if Mr Jackson was related to the famous Jackson family, which hails from Gary.