CANBERRA, March 14 (Reuters) - Australia is deeply concerned over the arrest of two Australian journalists in Malaysia after they attempted to question Malaysian Prime Minister Najib Razak over corruption allegations, Foreign Minister Julie Bishop said on Monday.

The journalists from the Australian Broadcasting Corporation’s (ABC) flagship investigative journalism programme, Four Corners, were arrested in the Borneo state of Sarawak on Saturday night after approaching Najib outside a mosque.

Malaysian police said in a statement the pair had been arrested for failing to comply with police instructions not to cross a security line. They were released on bail on Sunday and charged with “obstructing a public servant in the discharge of his public functions”.

Bishop told ABC radio Australia was “deeply concerned”.

“We are providing consular support to the ABC crew and certainly raising this issue at the appropriate level with the Malaysian government,” she said.

Najib has faced sustained pressure to resign since the middle of last year over allegations of corruption linked to the debt-laden state fund 1Malaysia Development Berhad (1MDB), and deposits into his private accounts worth around $680 million.

He has denied any wrongdoing and maintains he did not use the funds for personal gain. He was cleared earlier this year of any criminal offence or corruption.

Sally Neighbour, the programme’s executive producer, wrote on Twitter that the journalists had been in Malaysia reporting on the corruption scandal and denied any allegations of wrongdoing on their behalf.

“Our journalists were doing what journalists do in countries with a free press,” she wrote.

Reporter Linton Besser and camera operator Louie Eroglu have had their passports returned, Neighbour said, but have been barred from leaving the country.

Former Malaysian leader Mahathir Mohamad cranked up pressure on Najib to quit earlier this month, marking a seismic political shift by joining hands with long-standing foes, including the party of the jailed Anwar Ibrahim. (Additional reporting by Praveen Menon in Kuala Lumpur)