Malaysia intercepted and returned a shipment of North Korean military communications equipment sent to Thailand in 2011, the country's police chief said on Monday, amid growing scrutiny of the Southeast Asian nation's dealings with North Korea.

The comments come after Malaysia's foreign ministry this month rejected suggestions it may have violated U.N. sanctions on North Korea.

Ties between the two countries have been strained since the Feb. 13 murder of the estranged half-brother of North Korean leader Kim Jong Un at the airport in Kuala Lumpur.