The third series takes the form of a four-adventure box set entitled The Ordeals of Sherlock Holmes, featuring adventures from different stages of Holmes and Watson's lives.

'It was a really engrossing idea that writer Jonathan Barnes pitched to me when we recorded The Adventure of the Perfidious Mariner last year,' explains producer and actor Nicholas Briggs. 'Once I'd read the storylines, I was hooked and immediately commissioned the script.

'It's taken quite some time for us to schedule the recordings, mainly because I've been fiendishly busy on our Doctor Who range, with productions like Dark Eyes and The Light at the End,' continues Briggs. 'But finally, I got director Ken Bentley on board and we're now hoping for these stories to be released in December this year.'

Full cast details are not available yet, but Blake Ritson (Gods and Monsters, Counter-Measures Series 2 and Foe From the Future) features in a highly prominent role.

'We feel so lucky to get Blake, as he's been working hard on Da Vinci's Demons, and of course he has an amazing track record, appearing in so many things! Just look him up!' says Briggs.

Additional to The Ordeals of Sherlock Holmes, Big Finish will also be releasing a number of download-only Conan Doyle Holmes short stories audiobooks, performed by Briggs and Earl.

Pre-orders and discount subscriber opportunities will be announced in the coming months.

Meanwhile, Sherlock Holmes series 1 and 2 are still available.