Chris Gober was trying to persuade a Pennsylvania judge that the giveaway was not an "illegal lottery" as Philadelphia district attorney Lawrence Krasner alleged in a lawsuit seeking to block the contest before Tuesday's US presidential election.
"There is no prize to be won, instead recipients must fulfil contractual obligations to serve as a spokesperson for the PAC," Gober said in the hearing on Monday before Judge Angelo Foglietta, referring to Musk's political action committee, known as America PAC.
The hearing in the battleground state comes a day before Democratic Vice-President Kamala Harris and Republican former president Donald Trump square off in the tightly contested race.
Tesla CEO Musk has become an outspoken Trump supporter and promoted the former president on his X social media platform.
America PAC lawyer Chris Gober denies the recipients of its giveaway are chosen at random. (AP PHOTO)
Since October 19, he has been giving a $US1 million ($A1.5 million) cheque every day to a registered voter in one of the seven states expected to decide the election - Arizona, Georgia, Michigan, Nevada, North Carolina, Pennsylvania and Wisconsin - who has signed his petition supporting free speech and gun rights.
Krasner, a Democrat, sued Musk and his political action committee in state court on October 28 to try to block the giveaway, which he called an illegal lottery.
America PAC says its two remaining winners will be from Arizona and Michigan.
Chris Young, America PAC's director and Musk's political adviser, testified at the hearing there would be no further winners in Pennsylvania.
But in courtroom testimony, Krasner said he would seek financial penalties against Musk and America PAC.
A lawyer for Krasner's office, John Summers, showed the court a clip of Musk at an October 19 Trump rally saying America PAC would "randomly" award $US1 million to people who signed the petition.
In the video, Musk said "all we ask" was that the winners serve as America PAC spokespeople.
Summers called Gober's comments a "complete admission of liability".
Young said he was surprised to hear Musk describe the giveaway as random.
Young said candidates appeared in videos and gave the PAC permission to use their images, and that he personally selected winners after reviewing their social media and meeting them outside event venues, where they went onstage to receive the cheques.
He also acknowledged the winners signed non-disclosure agreements preventing them speaking about the terms of the contracts.
Musk's giveaway falls in a grey area of election law, and legal experts are divided on whether Musk could be violating federal laws against paying people to register to vote.
The US Department of Justice has warned America PAC the giveaway could violate federal law.
Musk has given nearly $US120 million to America PAC, according to federal disclosures.
