Police investigating the disappearance of Newbridge man Kyle Vaughan have arrested a 15-year-old boy from Abercarn – the fourth of the murder inquiry.
The teen was arrested on Sunday on suspicion of assisting an offender.
A 21-year-old man from Newbridge, also arrested on Sunday on suspicion of assisting an offender, remains in police custody assisting officers with their enquiries.
Gwent Police has also been granted an extra 24 hours to question a 27-year-old man arrested on suspicion of murder on Thursday.
A 62-year-old Newbridge man arrested on suspicion of perverting the course of justice on Saturday has been released on police bail pending further enquires.
Kyle Vaughan, 24, was last seen in the late evening of Sunday December 30 in the Abercarn and Risca areas.
On the same night at approximately 11.45pm, officers found Kyle’s car – a silver Peugot 306 – on the A467 between Risca and Crosskeys. It is believed the car had been involved in a collision and officers are appealing for anyone who saw the vehicle to come forward.
Mr Vaughan, who has diabetes and needs regular insulin injections, is described as 5ft 8ins, of slim build, with short dark hair, and brown eyes. He wears a gold neck chain with a cross and has a distinctive tattoo of a pair of flaming dice on his inner left forearm.
Police have told Mr Vaughan’s family they believe he is dead.
Officers continue to appeal for anyone with information to call 101 or Crimestoppers anonymously on 0800 555111.