In a lawsuit filed in a federal court in Los Angeles, Biden accused Giuliani, who has served as a personal lawyer for former President Donald Trump, and Costello of being responsible for the "total annihilation" of his digital privacy.

The legal action is the latest lawsuit filed by Biden as he prepares to plead not guilty to federal gun charges next week after an earlier plea deal with prosecutors fell apart.

Biden, 53, has also sued a former White House aide who served under Trump, as well as the U.S. Internal Revenue Service. Republicans have focused on Hunter Biden as President Joe Biden, a Democrat, seeks re-election next year.

His trial in Delaware over the federal gun charges is the first-ever prosecution of a sitting U.S. president's child, and comes as Joe Biden could again face Trump, who faces four upcoming criminal cases of his own, in 2024.

Trump and congressional Republicans, without evidence, have separately accused the Democratic president of profiting while he served as vice president from 2009 to 2017 from his son's foreign business ventures. The White House has denied the accusations.

Representatives for Giuliani and Costello could not immediately be reached for comment on the lawsuit.

The president's son accused the pair of claiming to have obtained data taken or stolen from his devices or storage platforms, including a laptop, but noted that Giuliani and Costello in public statements cited an "external drive."

"Although the precise timing and manner by which Defendants obtained Plaintiff's data remains unknown to Plaintiff, there is no dispute that Defendants have, at least to some extent, accessed, tampered with, manipulated, altered, copied and damaged Plaintiff's data, and that their actions are illegal, unauthorized, and without Plaintiff's consent," the lawsuit said.

Hunter Biden is seeking punitive damages and disgorgement of all money Giuliani and Costello may have obtained from their activities, as well as the restoration of any data they still possess that belongs to him, the filing said.

Earlier this month, Costello and his law firm separately sued Giuliani over more than $1.3 million in unpaid legal fees.

(Reporting by Jonathan Stempel; writing by Susan Heavey; editing by Jonathan Oatis)