British actor Tom Hiddlestone attends the Evening Standard Theatre awards in London November 30, 2014
British actor Tom Hiddlestone attends the Evening Standard Theatre awards in London November 30, 2014 Reuters/Neil Hall

Tom Hiddleston is starring in “Sherlock” as the third Holmes brother, says a report that has picked up momentum recently. The rumour adamantly claims that “The Avengers” favourite villain will be joining titular star Benedict Cumberbatch and Martin Freeman in the fourth season of the British series.

It’s an unsubstantiated report, and an unlikely one as well. Hiddleston is busy with the miniseries “The Night Manager,” which he co-stars in with Hugh Laurie (“House”) and Olivia Colman (“Broadchurch”).

The Parent Herald claims Gatiss was hesitant to cast Hiddleston at first because the actor has a lot of other commitments. Fans, the paper says, refused to be discouraged, though, reasoning out that Cumberbatch also has a busy schedule but can find time to film the series. For the record, the rumour that Hiddleston is playing a Holmes brother has been going on for years. The casting report is just too good to be true, though, and has refused to die.

There are a couple of holes in the rumour, though. There’s the “Sherlock Holmes” book fact that there are only two Holmes brothers: Sherlock and Mycroft (played by co-creator Mark Gatiss). Although Gatiss and co-creator Steven Moffat have artistic freedom on bringing Sir Arthur Conan Doyle’s characters to life, the British television adaptation has faithfully followed the original stories so far. It’s still possible that the producers and writers would deviate from the Conan Doyle’s novels.

There is, however, a hypothetical third brother in later adaptations of the novels. Sherrinford Holmes was not part of the Conan Doyle novels, but was added by other writers who adapted the series. The eldest brother is often depicted as a villain in the adaptations.

Nevertheless, arguments from Sherlock fans note that Mycroft himself hinted at a third brother in the season 3, episode 3 episode titled “The Last Vow.”

“You know what happened to the other brother,” Mycroft told Lady Smallwood (guest star Lindsay Duncan) when he was accused of sentimentality.

As some theories on Baker Street Wikia said, it could be that Sherrinford was Moriarty’s (Andrew Scott) mentor, while Mycroft was Sherlock’s. And as Moriarty turned out to be a villain, it could also mean Sherrinford is one.

However, even if there’s indeed a Sherrinford in the fourth season, Hiddleston might be too young to play him. As the adaptations said, he is the eldest brother. At 35, Hiddleston is in fact younger than Cumberbatch (39) and Gatiss (49).

So far, none of the “Sherlock” masterminds or the actors have confirmed or denied the news of the third brother or Hiddleston’s involvement.

“Sherlock” aired its Victorian-themed episode “The Abominable Bride” in January. It will resume production in April for the airing for its fourth season in 2017.