Visitors from China have claimed they were banned from a German military plane at a recent airshow, prompting an apology from manufacturer Airbus.
The incident allegedly took place at the Singapore Airshow, one of the region's largest exhibitions of commercial and military aviation.
The claims have gone viral on Chinese social media, sparking controversy.
German officials have yet to comment. Airbus said it was sorry for "any inconvenience caused".
In one widely-circulated video filmed by a Chinese blogger on the weekend, a woman wearing Airbus identification is seen asking him for his nationality.
The man was attempting to enter an Airbus A400M transport aircraft owned by the German air force, the Luftwaffe.
The woman tells him that she needs to check his nationality "because it is a German aircraft".
When he tells her that he is Chinese, she immediately refuses him entry, saying "it's German rules, it's military restrictions".
A BBC review found that several aspects of the video, including the planes seen in the background and the woman's ID, appeared genuine.
Other Chinese visitors have also claimed online that they were not allowed on the plane.
Another blogger said he was chased away by German military staff, and that he had lodged an official complaint with the airshow's organisers alleging "discrimination against Chinese people".
Commenters on Weibo pointed out that Chinese visitors were allowed to visit other countries' military aircraft, and lambasted Airbus and the German military.
When approached by the BBC, a representative at the German embassy in Singapore referred reporters to Airbus as they were "responsible for security and managing the entrance" to the plane. He did not respond to questions about the allegations regarding German military staff.
Airbus declined to comment on the video.
But the European plane manufacturer told the BBC they were aware that some visitors at the Singapore Airshow had "raised questions about access" to the A400M plane.
"We immediately communicated and coordinated with the customer and our Airbus teams at the show to ensure that the aircraft was open to all visitors for the remainder of the airshow. We sincerely apologise for any inconvenience this may have caused," they said.
Airbus posted a similar apology on its official Weibo account.
The BBC has also contacted the airshow's organisers and the Chinese bloggers for comment.
Airbus touts the A400M as the most advanced "airlifter" military transport plane available. It can deliver troops into small unprepared airstrips in the battlefield as well as send large equipment to bases, while also acting as a mid-air refuelling tanker.
The incident comes amid increasing European concern of Chinese state access to Western military technology.
The President of the European Commission Ursula von der Leyen last year warned against European technology enhancing China's military capacities.
