The Pope - probably not a Wales fan (Reuters)

Could there be any truth to the urban legend that claims every time Wales win a rugby grand slam a pope dies?

The hypothesis, based on the deaths of Paul VI, John Paul I and John Paul II in years when the Welsh team dominated the Six Nations, was rejected by doctors in 2008.

However, a letter published in the British Medical Journal has claimed the study made the fatal error of ignoring coptic popes.

In a revelation that could see popes locking themselves in armoured mobiles for the remainder of the year following Wales' recent success, Dr Edward Snelson claimed the 2008 study was based on "false assertions".

He quoted the study's urban legend basis, "Every time Wales win the rugby grand slam, a pope dies, except for 1978 when Wales were really good, and two popes died.

"However they included only Roman Catholic popes in their outcome measures, thus altering the statistical analysis to create a potentially false reassurance," he wrote.

His letter goes on to use the example of the death of coptic pope Shenouda III "on the very day that Wales won the grand slam".

"He was pope for 41 years and succeeded Cyril VI, who died in 1971, in the same month that Wales won the grand slam again," he adds.

"Coptic popes are the heads of the ancient seat of Alexandria and directly follow on from Mark the evangelist, thus having a legitimate claim to the title. it is crucial that this new information be brought to the attention of your readership".

The study in 2008 concluded: "The special theory of papal rugby is nothing more than an urban myth, based largely on two Welsh grand slam wins in recent memory.

"This comes as something of a relief, as we are at a loss to see how the events could be linked, especially considering the continuing rapprochement between Catholic and protestant churches."

Snelson warned that the study created a false reassurance and "may be putting the lives of other popes at risk".