(CNN)British sprinter Chijindu Ujah, who won a silver medal in the 4x100m relay at the Tokyo Olympics last week, has been provisionally suspended for a doping violation, the Athletics Integrity Unit (AIU) announced on Thursday.

If the suspension is upheld, all four members of Great Britain's relay team -- which finished behind Italy by one hundredth of a second in Tokyo -- face being stripped of their medals. Canada would be promoted to silver and China to bronze.