Cuggiono canal
A canal in Cuggiono (representation image) Luca Terzaroli/Flickr

A German boy has survived being trapped underwater for 42 minutes in what his doctor said was a one-in-a-million miracle.

The 14-year-old boy, identified only as Michael or Michi, was trapped six feet below water in a canal in Cuggiono, near Milan.

He became trapped after jumping off a bridge with friends on 24 April. When divers pulled him up to the surface, his heart had stopped and paramedics thought he was dead.

However, doctors were able to restart his heart with a defibrillator and CPR – much to their amazement.

He was then taken to hospital in Milan where Dr Alberto Zangrillo used a special technique to pump oxygen back into his bloodstream. He was attached to a machine that took over from his lungs and heart – the technique, called extracorporeal membrane oxygenation (ECMO), extracts oxygen-deprived blood, warms it then pumps it back into the body.

After a month he woke up alert and able to chat to his parents – he asked about his football team Juventus and for a mojito.

Zangrillo told the Times: "It's extraordinary, and some people are talking about a miracle. I have to see this from the point of view of medical science, but I cannot explain it completely.

"According to the rules, there is no point using ECMO if the patient's blood has stopped flowing for six minutes. After 15 days we performed an MRI scan and his brain appeared OK."

His leg had to be amputated, but he appears to have suffered no brain damage or memory loss.

The doctor told Italian newspaper Corriere della Sera he had little hope Michael would survive: "I told [his mother]: Michi has one chance in a million to make it, but without knowing what the outcome was to be."

Zangrillo added that the boy is "exceptional" and is able to joke with friends and family – even asking the doctor for a cocktail.

But how did he survive for so long underwater? There are a number of other cases where people have survived up to an hour underwater, but experts say young people have a better chance of living.

This is because of being able to drop the heart rate and divert oxygen to the brain – a reflex that is more prominent in younger children. Colder water is also better for sustaining brain power.