While defending its selection of persons to travel on a chartered flight to South Korea along with NA Chairwoman Nguyen Thi Kim Ngan to an economic forum, the Ministry of Planning and Investment has said it would deal strictly with involved parties if violations are found.

The ministry was responding to the controversy that has broken out over the disappearance of nine Vietnamese people who traveled with Ngan to the Vietnam –South Korea Investment and Trade Forum.

Two of them have since been deported, but no further details have been revealed about their identity, the timing of their deportation and whether or not they have been detained on arrival for investigation.

The investment ministry said it had properly selected and verified the list of business representatives to travel on the chartered flight, and sent it to relevant parties to double check. 72 members of 44 businesses from Vietnam joined the event.

But some people intentionally used the occasion to stay on illegally in South Korea, not collecting their passports from the agency that had collected them. The passports have been returned to Vietnam and handed over to concerned authorities, the ministry said.

In the 30 years that the ministry has organized business groups to travel abroad with national leaders, it is the first time such an incident has happened, it added.

On Wednesday, head of the NA Office Nguyen Hanh Phuc had confirmed that nine Vietnamese had illegally stayed in South Korea after going there on the chartered jet with Ngan, who'd been invited to make a speech at the forum as part of her official visit to South Korea last December.

The nine were not part of the Vietnam National Assembly's diplomatic group and were not granted diplomatic visas, he said.

Vietnamese police and South Korean authorities are trying to find and deport the remaining seven and would deal with them in accordance to the law, said Phuc, adding that the incident was "regrettable."