Hai, along with Tran Ky Hinh, former head of the Vietnam Register, were put under investigation by the Ho Chi Minh City police on Tuesday for abusing their positions of power for their own benefit.
Hai was detained that day, while Hinh had already been arrested for receiving bribes in another case, also involving violations regarding inland registration.
Four others at the river vessel division under the Vietnam Register have also been arrested for abuse of power: division head Bui Quoc Hung, deputy division head Dau Ngoc Binh, and staff members Phan Huy Liem and Vu Van Son.
The suspects have been accused of committing violations in the evaluation of facilities that build, repair and restore inland waterway vehicles.
In relation to the same case, on Dec. 22 last year Ho Chi Minh City police put nine people under investigation for giving bribes, receiving bribes, soliciting bribes, and obtaining property by fraud.
Among them, Do Trung Hoc, former head of the river vessel division, along with five others, had committed violations regarding the evaluation of the proficiencies of facilities, according to investigators.
A widespread investigation on violations regarding inland registration had resulted in 114 cases involving over 800 suspects last year.