Officers at the Wembley Stadium, a venue that hosted soccer events reported that a set of internal keys used on searches at the venue were missing, according to Scotland Yard.
While the detectives failed to trace the keys, they could not find any evidence of criminal offences which suggest that policemen had misplaced the keys.
"There is absolutely no security concern in relation to the stadium as measures were taken immediately to secure all key areas of the venue," police said in a statement.
Though the policemen did not give more details on the purpose of the keys, which were lost, the organisers of the prestigious event said that the locks have been changed and there was no security breach.
Wembley, one of the venues that host men and women's soccer tournaments during the Olympics, also hosted its first match on Wednesday, ahead of the opening ceremony.
Though it was a harmless incident, it shows the other facet of the arrangements, which is quite embarrassing for the officials who are already on the edge defending their security arrangements for the London Games.