Barotrauma and drowning caused the death of two British divers, a father and son, at Xwejni Bay on Wednesday, a post-mortem examination has shown.

Barotrauma is the physical damage caused to body tissues by variations in pressure.

John Avent, 58, and his son Rhydian, 16, were scuba diving in the limits of Xwejni, near Marsalforn, together with a small group of relatives and friends when they suddenly found themselves in difficulty.

Sources yesterday said it appeared that a group of six divers, including an instructor, were diving together at a depth of 17 metres. The divers were in groups of two and at one point the youngster was seen struggling and his father went to his assistance. The two were then seen going down, with the mother and the instructor rushing to grab them. They pulled them to the surface but they had already drowned, the sources said.

The divers had only been in the water for a few minutes when the accident happened.

Police sources said they were still keeping all options open and the equipment the divers were using would be tested.

"Initial indications do not point to anything being wrong, especially considering there were other divers using similar equipment in the same group. But we are keeping all our options open," a police source said.