• Sue Vertue, Amanda Abbington, Benedict Cumberbatch, Steven Moffat and Mark Gatiss attend the 'Sherlock' press line at Comic-Con International 2016 - Day 4 on July 24, 2016 in San Diego, California.

Sue Vertue, Amanda Abbington, Benedict Cumberbatch, Steven Moffat and Mark Gatiss attend the 'Sherlock' press line at Comic-Con International 2016 - Day 4 on July 24, 2016 in San Diego, California. (Photo : Getty Images/ Araya Diaz)

"Sherlock" Season 4, episode 3 was recently leaked online after someone illegally uploaded it on the Internet.

The finale episode, which is set to air on Sunday, Jan. 15, is expected to feature the return of one of the most intriguing characters in the history of the BBC One TV series.

Like Us on Facebook

According to The Independent, "The Final Problem" will also focus on Sherlock (Benedict Cumberbatch) and Moriarty's (Andrew Scott) heated interplay. The publication also noted that the finale episode for "Sherlock" Season 4 is expected to be shocking one because it could the very last episode for the franchise.

But series co-creators Steven Moffat and Mark Gatiss said that a renewal is still possible for their show. While speaking with the Guardian, Moffat and Gatiss admitted that their biggest problem has to do with Cumberbatch and Martin Freeman's schedule. The latter plays the role of Dr. Watson.

"We would love to do more, but we are not lying, we absolutely do not know. It is all up to all of factors, scheduling. Willingness to do it is all here, but we are just not sure," Gatiss said.

Other than Cumberbatch's schedule, Gatiss and Moffat will also be busy with "Doctor Who," of which the latter is the current showrunner.

Meanwhile, following the leak, executive producer Sue Vertue urged fans not to watch the leaked episode. On her Twitter account, Vertue posted a series of tweets saying that the leaked episode was from Russia.

In other news, "Sherlock" was recently criticized for having close resemblance to the storyline of "James Bond." While at the screening for the final episode, Moffat said that the third and final episode from the season will be different from all the previous episodes in "Sherlock" history.

"Sherlock" Season 4, episode 3 will air on Sunday, Jan. 15 at 9 p.m. EST on BBC One.