Police are appealing for information to find Joseph Bellamy, 18, who is missing.
Joseph was last seen leaving his home address in Caldicot between midnight and 1am on Tuesday 3 December.
He was later captured on CCTV cycling on a red pushbike towards the M48 bridge.
Joseph is described as white, 6ft tall with mousey hair and blue eyes.
He was last seen wearing light colour jeans with black high top Nike trainers and a black Teddy fleece jumper with a black sweatshirt underneath.
Anyone with information on his whereabouts is asked to call Police on 101 or send them a direct message on social media, quoting log reference 2400400170.
Police are also asking any motorists who were in the area, or travelling across the bridge, between 12.30am and 1.30am to check their dashcam footage.
Joseph is also urged to get in touch with Police.
