Don’t spoil the surprise – that is the warning Sherlock creators have issued after the final episode in the series was leaked online.

The culmination of the current three-part series four is due to air tomorrow night, titled The Final Problem, but a Russian version of the episode has already been leaked online.

Sherlock.
Sherlock concludes tomorrow (Robert Viglasky/BBC/PA)

Images apparently taken from the leaked episode had been circulating on social media today.

Sherlock producer Sue Vertue also tweeted that fans should wait just a tiny bit longer to find out what happens next.

The series, based on the novels by Sir Arthur Conan Doyle, stars Benedict Cumberbatch as Sherlock and Martin Freeman as his sidekick Dr John Watson.

On Thursday a special screening of the series finale was shown in London, with those attending the event urged to keep the plot a secret.

Sherlock’s series four finale airs tomorrow on BBC1 at 9pm.