Sgt Marks had intended to compete in the inaugural Games in London in 2014, but collapsed on the eve of the event with a serious lung condition and was put into an induced coma.

She was nursed back to health by a team from Papworth Hospital in Cambridgeshire and asked Prince Harry - the creator of the Invictus Games for injured armed forces personnel - to return the medal to them as he placed it around her neck. 

"I landed in London and became very ill, very rapidly, I was in hospital in London and went into respiratory distress syndrome," said 25-year-old Marks, who is from Arizona. 

"They shipped a team down from Papworth who put me on to ECMO [Extracorporeal membrane oxygenation] life support and that ultimately saved my life.

"I was on it for 10 days and ended up waking in an army hospital in Germany having no idea what had happened.

"But they absolutely saved my life and I can’t thank the UK enough for having that kind of medical support and taking such good care of me.

"So I gave Prince Harry one of my medals and hope it will find its way back to Papworth."

One of Marks’ four victories in Orlando came in the women’s 50 metres freestyle ISB, clocking a time of 34.45sec to finish ahead of Britons Jennifer Warren and Anna Pollock in 41.47 and 51.59 respectively.

She also had comfortable successes in the 50m backstroke ISB, winning in 40.16, and 50m breaststroke ISB with a time of 42.67.

Canada’s Christine Gauthier was second in the backstroke in 1:14.99, while Britain’s Susan Warner was third in 1:15.58.

Like in the freestyle, Warren and Pollock followed Marks onto the breaststroke podium with times of 1:01.10 and 1:14.41 respectively.

Marks' other triumph was in the women’s 100m freestyle ISB, touching home in 1:16.15 to fend off Warren, second in 1:34.45, and Pollock, third in 2:10.64, once more.

It was this gold medal that Marks, who in 2010 suffered a serious hip injury that left her with no feeling in her left leg, asked Prince Harry to return to Papworth Hospital. 

Elsewhere on the penultimate day of action, hosts the US beat Denmark 28-19 to claim the wheelchair rugby gold medal.

The US had earlier recorded a 36-15 semi-final victory over Australia, who went on to lose their bronze medal match against Britain 47-4.

Britain suffered a 31-26 defeat at the hands of Denmark in the other last-four encounter. 

New Zealand’s Kenneth Barnes and David Sheriff booked their place in tomorrow’s wheelchair tennis doubles final after winning their single-set semi-final against the US’s Javier Rodriguez and R.J. Anderson 6-0.

Awaiting them in the gold medal match is the British pairing of Alex Krol and Andy McErlean, who beat The Netherlands’ Rodney DeVries and Edwin Vermetten 6-2.

The US and The Netherlands will contest the bronze medal match prior to tomorrow’s final.