The company that manages Australia's immigration detention centres has told a Darwin court the public release of its security training manual could jeopardise national security.

Lawyers for three asylum seekers accused of assaulting officers in Darwin last year have sought access to the security training manual of SERCO.

The lawyers want to know if the officers used excessive force against their clients.

SERCO has sought a non-publication order, saying the public release of the manual could put the security of the Commonwealth and the safe running of detention centres at risk.

The documents contain policies and diagrams relating to the use of force, hostage survival techniques and search procedures.

A lawyer for one of the accused pointed out that the documents do not contain "state secrets" or "designs for a nuclear submarine" and should not be suppressed.

A lawyer for SERCO says publication could jeopardise the ability to safely use force and maintain safe custody of detainees.

The Darwin Magistrates Court will make a decision on Monday.