In the video, Dr Mahathir also expressed his gratitude to the Indonesian government for its cooperation in returning the seized super yacht to the Malaysian government.
"We are happy since the Equanimity yacht has been handed over to us by Indonesia", Prime Minister Mahathir Mohamad, who is on a tour to Japan, said in a Facebook post.
"On the vessel's expected arrival to Malaysia, it said: "[The] safest we can say is within 48 hours".
Cynthia Gabriel, a member of an official team set up to recover assets allegedly bought with stolen 1MDB money, said that the Equanimity being handed over to Malaysia was "very significant".
The 1MDB scandal led to his shocking electoral defeat in May and Najib is now facing charges.
Indonesian authorities impounded the boat on a request from the US Department of Justice, which is seeking to seize $1.7 billion of assets allegedly bought with money looted from Malaysian sovereign wealth fund 1MDB.
The former prime minister is expected to be released after having his statement recorded and to present himself at the Jalan Duta court complex the next day.
On Saturday, the Indonesian government agreed to hand over the yacht to Malaysia. His Malaysian passport has been revoked and an arrest warrant issued.
Lawyers representing the wanted financier, also known as Jho Low, filed a notice yesterday to a California district court to direct the U.S. government to reveal its knowledge of the yacht's transfer.
Najib set up 1MDB when he took power in 2009, but it accumulated billions in debts.
Mahathir said anyone who wants to claim ownership of the yacht must show proof that the vessel was not bought with stolen funds. His current whereabouts are unknown but Malaysian authorities have said they want to bring him back to the country and prosecute him.
The US Department of Justice has said more than $4bn was misappropriated by high-level officials from the fund and their associates.
Low, who has so far evaded arrest, issued a statement through his US attorney on Monday protesting the handover of the yacht as an "illegal act" for ignoring court proceedings in the United States.
Hishammuddin Hussein says Malaysia lost a good chance to join the global fight against terrorism by closing the Saudi-backed King Salman Centre for International Peace.