Custom officials found 23,520 bottles of Starorusskaya Vodka worth 700,000 Singapore dollars (406,976 US) on Wednesday in a container after their suspicions were aroused.

The scanner's image of the cargo "was atypical of fruit drinks," the Immigration and Checkpoints Authority said on its website.

"Officers then decided to conduct a thorough check of the container. Upon physical check, the contents were confirmed to be vodka," it added.

The cargo came from the Middle East and was likely to have been meant for sale to the local pubs and clubs here.

Since the September 2001 terrorist attacks in the US and the Bali bombings last year, Singapore has been on a heightened state of alert, beefing up its defences against potential threats to foreign missions, government buildings and other facilities.

SPACE.WIRE