"However, Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield, said "This is a good quality study but I don’t think it tackles the issue.

"If you’re using your phone for four hours a day, presumably it is out of your pocket for longer. That raises a big question: how is it that testicular damage is supposed to occur?"

He said mobile phone use may be a marker for other lifestyle factors known to affect sperm quality.

"Maybe people who use a phone for four hours a day spend more time sitting in cars, which could mean there’s a heat issue. It could be they are more stressed, or more sedentary and sit about eating junk food getting fat. Those seem to be better explanations than a phone causing the damage at such a great distance" he added."