WASHINGTON (REUTERS) - The computer network on the US Navy's newest class of coastal warships showed vulnerabilities in Navy cybersecurity tests, but the issues were not severe enough to prevent an eight-month deployment to Singapore, a Navy official said.

A Navy team of computer hacking experts found some deficiencies when assigned to try to penetrate the network of the USS Freedom, the lead vessel in the US$37 billion (S$46billion) Littoral Combat Ship programme, said the official, who spoke on condition of anonymity on Tuesday.

The Freedom arrived in Singapore last week for an eight-month stay.

"We do these types of inspections across the fleet to find individual vulnerabilities, as well as fleet-wide trends," said the official.

Cybersecurity is a major priority for the Navy, which relies heavily on communications and satellite networks for its weapons systems and situational awareness.

US Defence Department spokeswoman Jennifer Elzea said the Pentagon's chief weapons test agency addressed "information assurance vulnerabilities" for the Littoral Combat Ship in an assessment provided to the Navy.

"The details of that assessment are classified," Ms Elzea said.

The Navy plans to buy 52 of the new LCS warships in coming years, including some of builder Lockheed Martin's steel monohull design and some of an aluminum-hulled LCS trimaran design built by Australia's Austal.

The ships are designed for combat and other missions in shallower waters close to shore.

Freedom's first operational deployment was in the Caribbean Sea in 2010, where the ship participated in four drug transport busts and captured a total of five tons of cocaine.