Banging sounds have been detected in the massive search for the missing Titanic submarine as friends of the explorers fear that the five stuck onboard the vessel are running out of time - with the clock ticking to find the craft before it runs out of oxygen tomorrow.

The discovery of the noises has sparked fresh hopes that the passengers are still alive and could desperately be banging the side of the craft so that they can be detected on sonar - possibly with cups. But at 12,500ft - nearly two-and-a-half miles - below the surface, and with possibly just two vessels on Earth capable of rescuing them, time is running out to find the craft.

Five people are onboard, including British billionaire adventurer Hamish Harding, and on Tuesday the US Coast Guard estimated the 22ft long OceanGate Expeditions vessel had just over 40 hours of oxygen left as they remain in the depths of the Atlantic, which experts have likened to 'being in space'.

Titan lost communication with tour operators on Sunday while about 435 miles south of St John's Newfoundland during a voyage to the shipwreck off the coast of Canada.