The long-awaited Top Gun sequel trailer is causing a stir for more than just its aerobatic stunts.

Following its release last week, a few sharp-eyed fans have spotted that the Japanese and Taiwanese flags on the back of the famous leather bomber jacket worn by Tom Cruise have been replaced.

Watch: Top Gun: Maverick trailer

The patches appear to have been swapped with two random symbols in similar colours - leading to social media speculation that the change is down to the film being partly produced by Tencent Pictures, a Chinese film distributor and production company.

Journalist Mark MacKinnon first spotted the swap, tweeting images from both the original 1986 film and the trailer for Top Gun: Maverick, due for release next year.

He wrote: "There's a new Top Gun movie coming out. And Maverick is wearing the same leather jacket - only this time it's Communist Party of China-approved, so the Japanese and Taiwanese flag patches are gone (screenshot on right is from the new trailer)..."

There’s a new Top Gun movie coming out. And Maverick is wearing the same leather jacket - only this time it’s Communist Party of China-approved, so the Japanese and Taiwanese flag patches are gone (screenshot on right is from the new trailer)... pic.twitter.com/gUxFNFNUKX — Mark MacKinnon (@markmackinnon) July 19, 2019

Relations between Japan and China have long been fraught, with tensions rising in recent years over Beijing's South China Sea development, where it has reclaimed reefs and islands and built runways, hangars and missile systems.

And China still sees Taiwan as part of its territory to be reunified, despite the two sides being ruled separately since the end of the civil war in 1949.

However, a former navy pilot has responded to the online controversy, saying there is "no meaning" to the flag change.

In a tweet responding to MacKinnon's original post, Ward Carroll said: "The patch assortment on flight suits and jackets in the Top Gun franchise has always been a running joke (among running jokes) for those in the #NavyAir business. They are random in where they are placed and commands they represent. Seek no meaning because there is none."

The patch assortment on flight suits and jackets in the Top Gun franchise has always been a running joke (among running jokes) for those in the #NavyAir business. They are random in where they are placed and commands they represent. Seek no meaning because there is none. — Ward Carroll (@wardcarroll) July 19, 2019

Top Gun: Maverick sees Cruise reprise his famous role of Pete "Maverick" Mitchell, with his character now a flight instructor at the Top Gun school.

It is due for release in June 2020.