Performance-enhancing drugs are a major concern for rugby union and the switch from the amateur to professional era has played a major part in the issue, according to former England captain and coach Martin Johnson.

Fourteen out of 42 athletes banned in the past two years by UK Anti-Doping have come from rugby in England and Wales.

Johnson believes he has good reason to be worried about the increasing use of banned substances.

“When I started playing, did I think anyone around the international team was (using drugs)? – no chance,” said Johnson, who led England to 2003 World Cup victory.

“Would you be worried about it now? – absolutely. Things are more available, the internet, knowledge of it is more widespread,” he told the Times.

“People are taking them, by all account, for vanity reasons.”

Johnson, however, said the lucrative professional era had been the major contributing factor.

“Now the game is professional and we live in a different time where kids can see a livelihood and a good livelihood out of doing it, then you’ve got to be very careful,” he added.