Kenyan marathon runner Wilson Kipsang has been suspended from competition for violating anti-doping rules.
Kipsang - who won bronze in the 2012 Olympic marathon in London - has been provisionally suspended for whereabout failures and tampering with samples, the Athletics Integrity Unit said.
A tweet posted on its official Twitter account said: "The AIU confirms a provisional suspension against Wilson Kipsang Kiprotich of Kenya for whereabouts failures & tampering, both violations of the @World Athletics Anti-Doping rules."
Kipsang, 37, won the London Marathon in 2012 and 2014 and has also triumphed in the Berlin (2013), New York (2014) and Tokyo (2017) marathons.
His personal best of two hours, three minutes and 13 seconds makes him the equal sixth-fastest man in history.