A doctor who works for the Bulgarian national team has claimed that Stiliyan Petrov's illness is a result of the Chernobyl disaster.
The Aston Villa midfielder was diagnosed with acute leukemia last month.
Petrov was six years old when Chernobyl, a nuclear plant in Ukraine - 650 miles from Sofia - went into radioactive meltdown.
Dr Mihail Iliev told The Sun that radiation around Montana, where Petrov grew up, was 1000 to 1300 above normal levels in the aftermath of the disaster.
"It was in the late spring, the population was eating fresh radioactive vegetables and other foods," said Dr Iliev. "Many people who were kids back then suffered cancer because of this.
"We called them The Chernobyl Kids. Most were born in the same region as Stiliyan."
Campaign group Greenpeace have estimated that the disaster will eventually cause 200,000 cases of cancer.