A seven-inch knife is believed to have been found in a dressing room used by Chelsea's youth team at the Blues' training ground in Cobham.
An internal investigation was set up by the former Premier League champions, who questioned the Under-18s in a meeting regarding the blade.
The youngsters denied any knowledge of the knife and it is believed that a member of the coaching staff claimed that the blade belonged to a contractor who was carrying out work in the facility, according to the Daily Mail.
"The knife looked liked something out of a Rambo film," a Chelsea source is quoted as saying.
A club spokesman said: "A knife was found on the premises at a time when only cleaning and building contractors had been on site. The club has determined that it did not belong to any player or staff member as the area was sealed off and we are satisfied it is not a matter of concern. The matter is closed."
The youth team were reportedly warned of the dangers of knife crime.
Danielle Joynson
