An ABC Four Corners crew has been detained by Malaysian police after trying to question Prime Minister Najib Razak over a corruption scandal.

Reporter Linton Besser and camera operator Louie Eroglu were arrested in the city of Kuching on Saturday night, after approaching Mr Razak on the street.

Both were released without charge on Sunday, but have been told not to leave the country.

Their passports were initially seized but have since been returned.

A police statement obtained by the AFP news agency said they were held after they crossed a "security line and aggressively tried to approach the prime minister".

"Both of them were subsequently arrested for failing to comply with police instructions not to cross the security line," the statement said.

The program's executive producer Sally Neighbour said on Twitter the arrest was related to the crew's reporting of corruption allegations involving Mr Razak.

Loading

The Malay Mail Online media outlet said police were investigating the incident under Section 186 of the Penal Code, which relates to obstructing a public servant.

Loading

But Neighbour tweeted the team was "doing what journalists do in countries with a free press".

"There was no breach. In a democracy, journalists asking the PM questions is routine," she wrote.

Malaysian news agency Bernama quoted national police chief Khalid Abu Bakar as saying officials would "discuss with the Attorney General's Chambers [whether] to charge them".

Deputy Prime Minister Ahmad Zahid Hamidi said local and foreign media would not be sanctioned for covering events but "must perform their duties according to the journalism ethics", AFP reported.

Earlier this month, leaders from across Malaysia's political spectrum joined forces to call for the removal of the scandal-hit Prime Minister.

Mr Najib, 62, has been under fire for a year over allegations as much as $1.4 billion was deposited into his personal bank account. He has denied any wrongdoing.