Papua New Guinea police are investigating another bank robbery in which armed men kidnap bank employees to gain access to the safe.

PNG Correspondent Steve Marshall reports that three staff members from Bank South Pacific and their families were kidnapped over the weekend.

Armed men wearing police uniforms held the families in hotel rooms in the tourist town of Medang while the three workers were driven to the bank and forced to open the safe.

The workers were then locked in the hotel rooms with their families while the criminals escaped with an unknown amount of cash.

It's the second kidnap and robbery case involving Bank South Pacific this year.

Two months ago a bank manager's family was taken hostage in Port Moresby while other gang members forced him to hand over $US380,000 in cash from a bank in Kerema in Gulf province.

Produced by Radio Australia and Australia Network