Swiss authorities investigating alleged bribery involving former 1MDB officials last week said there were "serious indications" that about $4 billion had been misappropriated from Malaysian state companies. Singapore said this week it had seized a "large number" of bank accounts over possible money laundering linked to international investigations related to 1MDB.
The foreign announcements came on the heels of a decision by Malaysia's attorney-general to clear Mr Najib of wrongdoing over the payment from an unidentified source of $680m into his bank account. The attorney-general said the money was from the Saudi royal family. The prime minister's supporters say the cash was a political donation, rather than for personal gain.
The French submarine case also refocuses attention on the killing of Ms Altantuya, which has long dogged Mr Najib — he says unfairly. The murder has continued to provoke allegations and theories thanks to Ms Altantuya's social connections, a perceived lack of motive on the part of two police officers convicted in 2008 of killing her, and the brutality of an execution in which her body was blown apart by explosives. The murder verdicts were overturned on appeal in 2013 then reinstated last year by the country's highest court.
Both Mr Najib and Mr Baginda have denied Ms Altantuya was killed because she worked on the submarine contract and wanted money from it. Mr Baginda has claimed Ms Altantuya blackmailed him but says she was threatening to expose their relationship rather than any misconduct in the arms deal.
Mr Najib knew nothing about Ms Altantuya's killing and never even met her, the Malaysian government spokesperson said. He added that no legal process had ever implicated the prime minister. The police officers convicted of Ms Altantuya's murder were not Mr Najib's personal bodyguards, as has been claimed, but members of a unit that provides rotating protection for government officials and visiting foreign dignitaries.
Mr Najib was the victim of political smears over the Altantuya case, the spokesperson said, adding: "There is absolutely no evidence of any wrongdoing and there never will be."