Mary Gearin – Australia has rejected East Timor's arguments that it has the right to demand the return of materials seized in an ASIO raid last year.

East Timor is in the International Court of Justice at The Hague, demanding the return of documents and data seized in raids on the office and house of lawyer Bernard Collaery. The tiny nation says its national security and sovereignty was violated and that Australia has breached international law.

But John Reid from the Attorney-General's office says Australia is disappointed with East Timor's arguments in the hearing. He said the ASIO raids were lawful, justified and respectful of East Timor's rights.

Solicitor-General Justin Gleeson says Attorney-General George Brandis has given further undertakings to satisfy East Timor's concerns about the use of the seized materials. He says the material would not be communicated to anyone in government for any purpose other than for the protection of national security.

Mr Gleeson told the court the raids were prompted by the prospect that a serious crime was being committed, that is that a disaffected former spy was going to put classified information in the hands of a foreign state, relating to East Timor's allegations that Dili's cabinet rooms were bugged during negotiations ahead of the 2006 oil and gas treaty.

East Timor has argued the raids put Dili at considerable disadvantage in a current arbitration process in which it is challenging the validity the treaty and also in negotiating maritime boundaries. The seized material is thought to contain details of allegations that Canberra spied on Timor during the treaty negotiations.