Jet Li, the martial arts legend turned Singapore citizen, has found himself at the centre of one of the internet's stranger health conspiracies — and his rebuttal only fuelled the fire.

Rumours had been swirling online that the 60-something star had undergone a heart transplant, fuelled by his visibly aged appearance in recent years and his long-documented battle with hyperthyroidism, which he has discussed openly. Li responded the way celebrities now do: he posted a topless clip to refute the claims and show he was doing fine.

The internet was not convinced. Instead of settling the matter, netizens accused him of wearing "artificial skin" in the video — a claim as bizarre as it was baseless, but one that spread rapidly across Chinese-language social media.

Li, who took Singapore citizenship in 2009, has lived a quieter life in recent years, stepping back from the relentless action roles that made him famous in films from Shaolin Temple to Hollywood's Lethal Weapon 4 and The Expendables. His hyperthyroidism diagnosis, revealed years ago, already explained the physical changes his fans had noticed; the transplant rumour appears to have been pure fabrication.

The episode is a case study in the no-win dynamics of celebrity health speculation. Say nothing, and the rumours metastasise. Post proof, and the proof itself becomes the conspiracy. For Li — a man who once played invincible heroes — the strangest fight of his career is against an audience that refuses to believe his own body.

Li's career is the stuff of martial-arts legend. Discovered as a wushu prodigy in Beijing, he became a national sensation with Shaolin Temple in 1982, then defined a generation of Hong Kong action cinema with the Once Upon a Time in China series as the folk hero Wong Fei-hung. Hollywood came calling in the late 1990s — Lethal Weapon 4, Romeo Must Die, The One — and he spent two decades as one of the few Asian actors with genuine global box-office draw, later joining ensemble franchises like The Expendables and Disney's Mulan.

Off screen, Li took Singapore citizenship in 2009, citing the city-state's education system and environment for his family, and founded the One Foundation, one of China's most prominent private philanthropies, after his experience surviving the 2004 Indian Ocean tsunami in the Maldives. The hyperthyroidism he disclosed years ago — a condition that can dramatically alter appearance and energy — already accounted for the physical changes fans had noticed.

That a man with this record must now post topless videos to prove he has not had a secret heart transplant says less about Li than about the rumour economy he inhabits. In the attention marketplace, a fabricated health crisis outperforms a quiet life of philanthropy every time — and the "artificial skin" counter-conspiracy proves that for some audiences, no evidence will ever be sufficient.