Attorney-general Mohamed Apandi Ali risks being perceived as a "jaguh kampung" (home ground champion) if he fails to register an official complaint on US attorney-general Jeff Sessions' description of the 1MDB scandal as "kleptocracy at its worst", said a senior lawyer who represents Dr Mahathir Mohamad.

Mohd Haniff Khatri Abdulla said Apandi should file an official complaint with the US Embassy in Kuala Lumpur and demand an apology on behalf of Malaysia.

"At the same time, Apandi should also appoint a lawyer in the US to intervene in the legal process of forfeiture there if what is claimed by Sessions is false and show proof that Prime Minister Najib Abdul Razak is not involved in the scandal.

"If Apandi does not do this, he would be seen as a 'jaguh kampung' and 'pengecut antarabangsa' (international coward)," Haniff added.

Speaking at the Global Forum on Asset Recovery in Washington DC on Monday, Sessions said almost half of the US$3.5 billion (RM14.2 billion) corruption proceeds seized by the US government came from the 1MDB-related civil forfeiture suits.

He alleged that corrupt officials and their associates reportedly used the 1MDB funds for a "lavish spending spree" such as US$200 million (RM813 million) for real estate in South California and New York, US$130 million (RM529 million) in artwork, US$100 million (RM406 million) in an American music label and a US$265 million (RM1 billion) yacht.

Haniff (photo) added that in the past, Najib or Apandi had merely denied such allegations on statements made by the foreign authorities on purported wrongdoing or crime related to 1MDB, without giving a detailed or logical response.

Following this assertion made by Sessions in Washington, the lawyer said Apandi must respond to refute the claims by taking the necessary actions he had stipulated above.

In January last year, Apandi, a former Federal Court judge, had cleared Najib of any wrongdoing.

On Aug 1 last year, Apandi, in responding to the US Department of Justice suits filed in July 2016, said he was contemplating to send representatives or to go and observe the proceedings there himself.

"I am pondering sending representatives there or going there myself just because we want to register our interest. If you want to give the money to us, we want to hear."

However, Minister in the Prime Minister's Department Azalina Othman Said (photo) told Parliament more than four months ago that the AG's Chambers had no plan to send lawyers to the US to observe the DOJ civil forfeiture suits linked to 1MDB.

Azalina said Putrajaya respects the rule of law and the DOJ's freedom to initiate legal proceedings it deemed necessary.

"The Malaysian government also takes note that the civil suits are currently under the US judiciary and that no criminal action has been initiated against any individual for criminal misconduct, and that there has been no court decision on the matter," Azalina said in a written parliamentary reply dated July 24.