Transport Minister Anthony Loke said today that Singapore's Transport Ministry was selective in the release of documents regarding the bilateral dispute over the use of Malaysian airspace.

The documents released were an extract of the minutes of a consultative meeting between Singapore and Malaysia on the proposed Instrument Landing System (ILS) procedure for the republic's Seletar Airport on Dec 5, 2017.

It also included letters dated Dec 6, 2017, and June 6 this year from the Civil Aviation Authority of Singapore (CAAS) seeking feedback from the Civil Aviation Authority of Malaysia (CAAM), which Singapore said went unanswered.

However, Loke said the documents released were selective, and asked his counterpart to release further communications between the two countries.

"The disclosure is only partial and selective with the primary aim of influencing public opinion.

"Malaysia's Transport Ministry hereby urges Singapore’s Transport Ministry to also release the letters from the CAAM to its Singaporean counterpart CAAS dated Oct 9, Nov 15 and Nov 21 and Nov 28.

"Failing which we are prepared to release the letters for full disclosure of such information for the public’s comprehension of our stand on the same," he said in a statement.

Malaysia had protested against Singapore updating the ILS runway approach protocol at Seletar Airport, which uses Malaysian airspace, and is due to come into force on Jan 3.

Loke said this was against the principles of national sovereignty as provided for by the Convention of International Civil Aviation.

However, Singapore claimed Malaysia had not previously raised objections over the matter.