'Sherlock' season 4 spoilers: 'Outlander' star unlikely to play 3rd Holmes brother

For a while now, there have been rumors going around that "Sherlock" season 4 will feature the third Holmes brother. New reports suggest the show has found the actor for the part.

"Outlander" lead actor Sam Heughan was reportedly tapped to play the role. No information verifies this yet, though. In fact, there is no confirmation on the arrival of the Sherlock (Benedict Cumberbatch) and Mycroft's (Mark Gatiss) sibling in "Sherlock" season 4.

Reports appear to justify the possible inclusion in a Twitter exchange between him and "Sherlock" executive producer Mark Gatiss that took place almost a couple of weeks ago.

Heughan, who is currently filming the third season of "Outlander" since September, greeted Gatiss a happy birthday, with him replying "Thanks pet! When do I get to see you?"

Fans tweeted out to both the artists, suggesting that they should work together. One suggested a guest appearance on "Sherlock" while another hoped for a "Doctor Who" showing.

Other than that, there was no confirmation of Heughan taking on the role of Sherrinford Holmes, whose deduction skill is believed to be far greater than that of his brothers.

There were tons of reports about the eldest Holmes brother to arrive in "Sherlock" season 4. Back then, rumors were rife about "Thor" star Tom Hiddleston playing the character.

The appearance of the character remains unconfirmed, but if "Sherlock" season 4 will be last (as suggested by Cumberbatch himself, fans are hoping to see all three Holmes brothers together.

Filming for the upcoming season, which has three episodes, is already complete. It began in April this year and ended July. Heughan was not on the set of "Outlander" by that time yet since the production for the Starz hit began just last month.

"Sherlock" season 4 is expected to premiere January next year on BBC. One of the characters fans look forward to seeing, apart from Sherrinford, is James Moriarty (Andrew Scott).