Umno lawyer Hafarizam Harun has denied knowledge of the US$3.657 billion lawsuit filed against Prime Minister Najib Abdul Razak and 15 others for US$3.657 billion over the losses incurred by 1MDB.

Contacted for response on the suit filed by Parti Bebas Rasuah (PBR) president Mohd Ezam Md Noor, Hafarizam said he has yet to receive any information on the matter.

"I cannot comment because there is no information or documents (received) on the suit.

"Also, I am not sure whether the documents have been submitted, to whom it was submitted, when it was submitted and others," he told Malaysiakini in a text message today.

Hafarizam said this when asked whether he had received instructions to respond to the suit filed at the Kuala Lumpur High Court yesterday.

In his statement of claim, Ezam, who is a former Umno senator, said the 16 are jointly responsible for the matter.

Najib is being sued in his capacity as finance minister and chief executive of the government while 1MDB and the government are also named as defendants.

The other defendants are treasurer-general Mohd Irwan Serigar Abdullah, 1MDB president Arul Kanda Kandasamy and two current and nine former 1MDB directors.

Ezam, who was represented by lawyer Farez Jinnah, accused them of intentionally causing "wrongful losses" for 1MDB.

The US$3.66 billion total sum claimed by Ezam came from US$1.03 billion transferred to Good Star Ltd and used for a joint venture with PetroSaudi International Ltd, US$1.367 billion paid to Aabar BVI and US$1.26 billion paid to Tanore Finance Corporation (TFC).