BBC series "Sherlock" is reportedly getting beefed up in Season 4 with the arrival of another Sherlock brother. Rumor has it that the new brother will be none other than famous actor Tom Hiddleston. Although nothing is confirmed at this time, it is the strongest rumor going around, Bustle reported.

It is a casting rumor that looks to be tailored to make fans of the series go crazy on the internet from their curiosity. There are times when a rumor such as this seems so perfect that it seems like a work of fiction or it could actually be a casting coup.

However, in the original story of Sir Arthur Conan Doyle, a third brother did not exist. He is an invention of William S. Baring-Gould, as chronicled in the so-called biography of Sherlock Holmes that he wrote -- "Sherlock Holmes of Baker Street: A Life of the World's First Consulting Detective."

Still, he was mentioned during the Season 3 finale by Mycroft when he was talking to Sherlock. From that bit of information, fans learned of his name: Sherrinford Holmes. Fans have accepted the name, but from all indications, it looked like he was dead.

However, if he was not dead and the rumor is indeed true that he will be played by the uber-charismatic Tom Hiddleston, what would fans do? There would be a grand field day for sure.

According to Christian Today, the possibility of Tom Hiddleston joining the cast as the third Holmes brother was hinted at by the show's co-creator Mark Gatiss during an interview in Brazil. It was issued as a joke with Gatiss saying that Hiddleston was only doing movies at the moment but that he could ask the actor, he told the interviewer.

So now top people involved in the show, like Steven Moffat, are busy fending off questions about the rumor. They are not denying the possibility but they are keeping mum about it. For now, fans of the show will have to be satisfied with the rumor and hope it comes true.