The weapon, which was discovered by a passenger, was left there by a novice air marshall on April 6, according to a report from CNN. The airline told the news channel it was aware of the incident, but declined to comment further.
The federal agent involved is still on active duty, according to sources quoted by CNN.
The US news channel also quoted a report commissioned by the US Transportation Security Administration, which employs air marshalls, which found that 84% of marshalls on international flights were identified as sleep-deficient.
The TSA said that air marshalls’ schedules ensured ‘appropriate rest periods’.