A Gwent youngster died in a holiday scuba-diving tragedy with his father off the Mediterranean island of Gozo.

Rhydian Avent, 16, who had just completed his GCSEs at Monmouth Comprehensive School, was diving on a family holiday with father Richard, 58, and mother Dr Sian Rees when the father and son got into difficulties and the distraught mother and diving instructor they were with battled in vain to save them.

It is understood that Dr Rees, said to be a more experienced diver than her husband and son, had descended with the instructor to 70ft in the area of Xwejni Bay, near Marsalforn on the island near Malta, on Wednesday. The father and son from Raglan had stayed nearer the surface at around 50ft.

But just five minutes later, the instructor saw them holding hands, and Mr Avent was struggling to inflate part of his diving equipment to take him back to the surface.

Dr Rees brought her son to the surface and and the instructor tried to rescue Mr Avent.

Dr Rees and the instructor desperately tried to resuscitate them. But the father and son were pronounced dead at the scene, Maltese officials said. Post mortem examinations showed that the father and son drowned.

Rhydian's older sister and brother, Cerian, 22 and Tomas, 21, were not on the holiday. Mr Avent was Welsh historic monuments agency Cadw's chief of ancient monuments and historic buildings. Dr Rees is also a senior official with Cadw.

Police in Malta are now investigating how the deaths happened.