Attorney-general Mohamed Apandi Ali's reaction to the latest US Department of Justice (DOJ) allegations on the misappropriation of 1MDB funds was "laughable", said Parti Pribumi Bersatu Malaysia (Bersatu) chairperson Dr Mahathir Mohamad.

In his first blog post since the DOJ's latest court filing last Thursday, the former premier said Apandi's "frustration" that Malaysia was not consulted by their US counterparts was a mystery because Malaysia's prosecutors never cooperated with Swiss investigators.

"But the AG is not known for cooperating on 1MDB investigations with foreign counterparts. The Swiss attorney-general has said this clearly.

"He stated 'despite repeatedly saying it (the Malaysian AG's Chambers) will cooperate with any foreign agencies investigating the 1MDB scandal, (it) refused to reply to the Swiss attorney-general office request for detailed information on the issue'," wrote Mahathir.

He was referring to Swiss attorney-general Michael Lauber's repeated claims that his Malaysian counterpart had not responded to mutual legal assistance requests.

What was Apandi expecting?

Mahathir also argued that Apandi's "frustrations" with the DOJ for failing to inform Malaysia's AG's Chambers were unfounded since the alleged money laundering took place in the US.

"Whether the criminals are Malaysian or not is irrelevant. Is the Malaysian AG expecting to intervene in the release of the 250-page statement?

"Is he expecting to get the DOJ to declare that the statements are official secrets, to be hidden from the public? Does he expect the DOJ to declare that there have been no wrongdoings based on the statements?...