There is no travel restriction against Dr Mahathir Mohamad, who has been accused of masterminding a plot to oust Prime Minister Najib Abdul Razak.

A check on the Immigration Department website showed that his travel status is 'tiada halangan (no restrictions)'.

Mahathir has repeatedly called on Najib to step down and has been a staunch critic of 1MDB.

He has warned that if Najib continues to lead, BN and Umno would be defeated in the next general election.

Following The Wall Street Journal report which claimed that RM2.6 billion of 1MDB-linked funds was deposited into the prime minister’s personal accounts, Najib took a swipe at his former mentor.

"The latest allegation is that I have taken state-linked funds for personal gain.

"I believe Tun (Mahathir), is working hand in glove with foreign nationals, including the now discredited political attack blog Sarawak Report, is behind this latest lie,” he had said.

The authorities have so far imposed travel bans on opposition lawmakers Rafizi Ramli and Tony Pua.

Also barred is The Edge media group owner Tong Kooi Ong.

Police sources have claimed that all three are being investigated under Section 124 of the Penal Code in relation to activities detrimental to parliamentary democracy.

This over allegations that documents related to 1MDB were fabricated to smear Najib.

Travel ban possible for Dr M

At a press conference earlier, DAP supremo Lim Kit Siang said a travel ban could be imposed on Mahathir.

"Many strange and extraordinary things are happening in the corridors of powers.

"I think that (Mahathir's travel ban) is very possible, we've seen a feverish pitch, this is a government tottering on its last legs here," he said.

Meanwhile, Serdang MP Ong Kian Ming also said checks with the Immigration Department website showed that both Shahrol Halmi and Arul Kanda, the former and current 1MDB top bosses were not banned.

A special task force is probing the allegations surrounding 1MDB, including the alleged RM2.6 billion in Najib's accounts.

This prompted Lim to call for a travel ban to be imposed on the prime minister.

Similarly, Malaysian Indian Progressive Association (Mipas) secretary-general S Barathidasan said Najib and Arul Kanda should be restricted from travelling overseas.

"There is the allegation of RM2.6 billion of 1MDB-linked funds having gone into Najib's personal bank accounts and that money has been used for the last general election.

"So all those related to the special task force's probe must not be allowed to leave the country, and this includes the prime minister," he told Malaysiakini.

He also asked if the ban was imposed on Mahathir.