KUALA LUMPUR - Malaysia summoned the high commissioner from neighbouring Singapore on Tuesday over a media report that said the city-state helped facilitate US-Australian surveillance in the region.
Foreign Minister Anifah Aman had already summoned the heads of the US and Australian missions earlier in November in protest over reports that a vast US-led surveillance network included a listening post in America's Malaysian embassy.
Malaysia is "extremely concerned" about the Singapore report, foreign minister Anifah Aman said in a statement.
"If those allegations are eventually proven, it is certainly a serious matter that the Government of Malaysia strongly rejects and abhors," he said.
Singapore's High Commissioner, Ong Keng Yong, confirmed to AFP by phone that he would be visiting the foreign ministry at midday.
Monday's report in the Sydney Morning Herald said Singapore and South Korea were playing key roles in a "Five Eyes" intelligence network involving the United States, United Kingdom, Australia, Canada and New Zealand.
It quoted a top-secret US National Security Agency (NSA) map that it said was published by Dutch newspaper NRC Handelsblad.
As a major hub for regional telecommunications traffic, high-tech Singapore was an important link in the surveillance network, it said.
The United States is struggling to dampen a global controversy over its eavesdropping activities.
Based on leaks by fugitive US intelligence analyst Edward Snowden, the revelations have included reports that the NSA monitored German Chancellor Angela Merkel's phone and sparked a trans-Atlantic rift.
The Sydney Morning Herald reported earlier this month that a map leaked by Snowden showed 90 US surveillance facilities at diplomatic missions worldwide including in Cambodia, China, Indonesia, Malaysia, Myanmar and Thailand, sparking anger in some of those countries.
The latest report comes as Malaysia and Singapore move to put decades of testy relations behind them, working together on real estate development along their border and pushing plans for closer transport links.