Police opened an investigation last month into an al-Jazeera documentary on the treatment of undocumented migrants after officials complained it was inaccurate and biased.

Seven al-Jazeera staff members - including five Australians - have been grilled by police as part of the probe for alleged sedition, defamation and violating the Communications and Multimedia Act.

Al-Jazeera, a Qatari state-owned broadcaster, said in a statement that police seized two computers during Tuesday's raid, which it called "an attack on press freedom as a whole".

It urged Malaysian authorities to cease the criminal investigation.

"Conducting a raid on our office and seizing computers is a troubling escalation in the authorities' crackdown on media freedom and shows the lengths they are prepared to take to try to intimidate journalists," said Giles Trendle, managing director of al-Jazeera English.

"Al-Jazeera stands by our journalists and we stand by our reporting. Our staff did their jobs and they've got nothing to answer for or apologise for. Journalism is not a crime," he said.

The documentary, titled Locked Up in Malaysia's Lockdown, investigated undocumented immigrants it said were at risk during the coronavirus pandemic.

Australian Associated Press