The International Court of Justice, the highest court for United Nations, made a milestone decision ruling against Australia in its $40 billion dispute involving oil and gas reserves in Timor Sea.

"Australia shall not interfere in any way in communications between Timor Leste and its legal advisers in connection with the pending arbitration under the Timor Sea Treaty of 20 May 2002 between Timor Leste and Australia; with any future bilateral negotiations concerning maritime delimitation; or with any other related procedure between the two states, including the present case before the court," ICJ president Peter Tomka said.

The ruling was supported by 15 of the ICJ's panel of judges.

Conversely, ICJ ruled for the Australian government to seal all documents and data obtained during a "raid" conducted by ASIO in December.

The raid was authorised by Attorney-general George Brandis. The raid involved dozen agents rummaging East Timor's Australian lawyer Bernard Collaery's office for classified paperwork including legal documents, electronic data and a copy of a statement by a former Australian Secret Intelligence Service agent admitting that Australia is "eavesdropping" on East Timor.

On Jan 21 2014, Mr Brandis had already vowed not to open any data and documents obtained through the raid, but the court deemed that risk of having these files exposed is still imminent.

"... the court finds that there remains a risk of disclosure of this potentially highly prejudicial information. In spite of the written undertaking [by Senator Brandis] dated 21st January 2014, there is still an imminent risk of irreparable prejudice. This was because the material contains sensitive and confidential information [relating] to the pending arbitration and it may also include elements that are pertinent to any future maritime negotiations which may take place between the parties," Judge Tomka said.

Court documents said that Australia shall ensure that the content of the seized material is not in any way or at any time used by any person or persons to the disadvantage of Timor-Leste until the present case [before the ICJ] has been concluded; and that Australia shall keep under seal the seized documents and electronic data and any copies thereof until further decision of the Court.