Speaking in a briefing on Monday, Senior Superintendent Iu Wing-kan said the latest suspects are five men and one woman aged between 16 and 25.
Some are suspected to have triad links, Iu said.
Two of them were nabbed in Hong Kong while the other four were arrested by Shenzhen authorities.
“These four suspects were formally handed over from the mainland to the Hong Kong police. We immediately arrested them on charges of conspiracy to commit robbery,” Iu said.
“Two other men were arrested locally over the past three days, also on charges of conspiracy to commit robbery.”
He also said the latest arrests included the alleged mastermind of the group, an insider and those who carried out the robbery.
According to the police, a 36-year-old man was ambushed at the airport car park during the small hours of Thursday by three masked assailants who escaped with six one-kilogram gold bars worth HK$7 million.
Officers said they’re still actively tracing the whereabouts of the gold bars.