condor airlines
A new Condor airlines Airbus A321 stands on the tarmac on the day of its christening at Schoenefeld Airport in Schoenefeld, Germany, June 5, 2013. Sean Gallup/Getty Images

A German airline issued warnings to its pilots after they allegedly filmed some stewardesses engaged in sexual acts on planes and circulated the videos around, reports said.

Holiday carrier Condor Airlines, owned by British travel giant Thomas Cook, was compelled to threaten the pilots with a two-year jail term in a letter released by the company on June 12, German magazine Focus reported Friday. In the letter accessed by the news magazine, pilots were warned of "criminal relevance" of "secret video footage and its distribution."

READ: Video Of Couple Having Sex On Ibiza-Bound Flight Goes Viral

"We have learned of the following facts: within the circle of the pilots, there are obviously some colleagues secretly taking photos and/or video recordings of the female colleagues who show the affected persons in clear sexual acts," the letter read.

The report also stated the videos were then distributed among colleagues without the consent of the persons concerned. However, during an internal investigation, the airline did not find any such videos, reports stated. Reacting to the reports, the airline stated it did not have any evidence or statements that confirmed the claims.

Condor warned the pilots of “serious consequences” including dismissal from job and criminal proceedings. The company said: "We are rigorously pursuing any allegation. We will, of course, initiate disciplinary and legal measures if we find that there is any substance to any kind of claim. We have informed our employees of the rumors and reminded them of our strict code of conduct which we expect all employees to adhere to at all time," reported The Local. It is not clear if the stewardesses violated any rules by engaging in sexual acts on planes.

This is not the first time that an alleged sexual act, filmed or photographed on an airplane, prompted a reaction from the airline. A pilot of British Airways was suspended in October after pictures emerged of a man — thought to be the pilot himself —performing a sex act wearing women’s stockings.

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In an incident in June, that involved flight passengers, a video of a couple appearing to engage in a sexual act aboard a Ryanair flight from Manchester to Ibiza went viral, prompting the airline to issue a statement condemning the incident. “We are looking into this matter. We will not tolerate unruly, disruptive or inappropriate behavior at any time and any passengers who appear to behave in an unacceptable manner may be liable for further sanctions,” the airline said. The couple, however, maintained that no intercourse happened.

Another passenger couple who performed a similar act on a Southwest Airlines flight in August was questioned by police and was let off without any charges. A statement by Southwest Airlines said: “On Saturday, two passengers traveling on Southwest flight 3246 from Atlanta to Las Vegas were engaged in inappropriate activity. Our Crew became aware of the situation and approached the Customers to address the behavior. The situation escalated and the Crew contacted local authorities to meet the flight.”

“Southwest does not condone this type of behavior and we apologize to the other passengers onboard who were potentially exposed to this activity,” it further read.