AceShowbiz -

It's bad news for BBC's "Sherlock" fans. According to series creator, writer as well as actor Mark Gatiss, the series may not return for another season as it has been a challenge for him to find time when both the main stars, Benedict Cumberbatch and Martin Freeman, can film together.

"I honestly don't know if there will be any more. It's incredibly difficult to get Benedict and Martin's diaries to align," Gatiss, who plays Mycroft Holmes on the series, revealed to The Sun at WhatsOnStage Awards. He added, "And obviously we left it in a very happy place...if that's the end I'd be very happy where we left it."

There has also been a rumor circling around claiming that Cumberbatch and Freeman are "hardly close." The two stars reportedly never hang out together outside the series. An insider told The Sun, "Benedict and Martin aren't mates and they don't spend time together away from the show." The insider added, "They're professional and very polite to each other but there's not the warmth you'd expect after filming together for six years." According the newspaper, they also allegedly didn't have a "huge desire" to return for a fifth season.

Should Cumberbatch decide to quit the series, the possibility that there will be no more "Sherlock" is higher. Gatiss had said that he would not continue the program without its leading man. "We couldn't do it without him, of course not," he told Daily Star in a separate interview.

He continued, "We couldn't recast Sherlock. It's not a show we're just churning out. It's a special thing and we couldn't do it without Benedict. We're very lucky to have the keys to Baker Street at the moment." He added, "Benedict and Martin have become the definite Holmes and Watson of our age. I don't think you need to argue that. The characters are immortal and when we finish there will be more interpretations."