Jamie Linton, 22, died following the crash
A 22-year-old man was killed after the car in which he was travelling crashed and overturned into a drainage ditch, known as a reen.
Jamie Linton died after the Vauxhall Corsa left the road and overturned on a road known locally as Sea Wall Road in Magor near Newport on Friday evening.
There was no other vehicle involved. Five other people suffered minor injuries in the crash.
A man, 19, has been released on bail after being arrested over the incident.
Police divers are continuing their search of the water in the reen to recover any personal belongings of those involved in the incident.
In a family tribute to Mr Linton, his relatives said: "Jamie will be sadly missed as a father, son, brother, grandson, nephew and dear friend of many.
"A nicer more polite boy you could never meet."
Flowers have been laid at the scene where the car went into the reen
Superintendent Nigel Russell from Gwent Police said: "Sometime during that evening on Friday night, a car driven by a local man was driven down this road with six people on board and has unfortunately lost control and has driven into the reen.
"It went upside down and one of the occupants has unfortunately drowned."
Supt Russell said three of the car's passengers were teenage girls, two aged 17 and one aged 16 and all from the Risca area.
The other three, including Jamie Linton, were young men from the local area and aged between 19 and 22.
He said the police were treating the incident seriously.
"We have arrested a local man who was the driver and are treating it very seriously," he said.
"In fact we are looking at it as manslaughter or even death by dangerous driving."
Police divers were at the scene on Sunday trying to locate any items belonging to the car passengers and anything which would help the police inquiry.
Supt Russell said the keys of the car had not yet been located.
He said the incident highlighted how the inexperience of young drivers could lead to accidents.
"This is a tragic example of what happens when something goes wrong," he added.
Gwent Police are appealing for witnesses to the incident to contact its Collision Investigation Unit on 01633 643091 or 01633 838111.