He was charged in court on Thursday in relation to the alleged transfer of $556m (£421m) from state fund 1MDB into his personal bank account.
He was also charged with four counts of abuse of power.
Mr Najib has pleaded not guilty to all 25 charges.
The latest charges come on top of three counts of money laundering levelled against him in August.
Mr Najib, members of his family and several allies are accused of embezzling huge sums allegedly used to buy everything from artwork to high-end real estate around the globe.
The allegations played a central role in his defeat in an election that was eventually won by his former mentor and long-time PM, 93-year old Mahathir Mohamad.
1MDB, set up by Mr Najib in 2009, was meant to turn the capital, Kuala Lumpur, into a financial hub and boost the economy through strategic investments.
Instead, it started to attract negative attention in early 2015 after it missed payments for some of the $11bn it owed to banks and bondholders.
Then the Wall Street Journal reported it had seen a paper trail that allegedly traced close to $700m from the fund to Mr Najib's personal bank accounts.
Billions of dollars are still unaccounted for.
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