National collegiate champion Taishi Narikuni has been handed a two-year ban by the Japan Anti-Doping Agency for failing a drug test, it was announced on Thursday.

According to a source familiar with the matter, the 20-year-old wrestler from Aoyama Gakuin University underwent a test after the Oct. 21-22 national collegiate Greco-Roman style championships in Hiratsuka, Kanagawa Prefecture, and the sample came back positive.

The source said Narikuni insists the substance was in a cold medication he took, but the public relations office from his university released a statement saying "We are taking this matter very seriously and offer our deepest apology."

Narikuni represented Japan at the world junior wrestling championships held in Finland in August. Later the same month, he completed a double by winning the 61-kg freestyle and 59-kg Greco-Roman at the national collegiate wrestling championships.