Democratic Republic of Congo's Cedric Mandembo, who lost his only judo match in 49 seconds to Russian Alexander Mikhaylin in the 100 kg category, disappeared shortly after Sunday's closing ceremony and was not answering his mobile phone, U.N.-sponsored Radio Okapi reported, citing the Congolese Olympic Committee.
Congo judo coach Ibula Masengo, boxing trainer Blaise Bekwa, and national technical director of athletics Guy Nkita had also gone missing, according to the report, which said all four had left the Olympic village with their luggage.
No further details were immediately available in London and a government spokesman said the Home Office did not comment on individual cases.
Olympic officials are also looking for seven Cameroonian athletes who went missing during the Games. Cameroon officials asked for help tracking down five boxers, a swimmer and a soccer player, and said they were probably seeking to stay in Europe for economic reasons.
The London Olympic organising committee said it had notified British police about the missing Cameroonians, but added that the athletes would not be infringing immigration laws until their visas expired in November.