Ruby Rose has chosen to ''stay silent'' on her decision to leave 'Batwoman'.

The 34-year-old actress starred as Kate Kane and her titular alter-ego in The CW series during its first season - which began airing last year - but made a shock announcement last week that she is stepping away from the iconic role and despite much speculation as to the reasons behind her departure, she has offered only a cryptic response and merely said ''those who know, know''.

Alongside a video montage of show footage set to 'Last Time' by Reece, she wrote on Instagram: ''Thank you everyone for coming on this journey. If I mentioned everyone it would be 1000 tags.. but Thank you to the cast, crew, producers and studio.

''It wasn't an easy decision but those who know, know.. I didn't want to not acknowledge everyone involved and how big this was for TV and for our community.

''I have stayed silent because that's my choice for now but know I adore you all. I'm sure next season will be amazing also. Xxx *hangs up cowl and cape* (sic)''

It was claimed a few days after Ruby announced her departure that she was unhappy with the long hours required as series lead, which led to friction on set, and ultimately the mutual decision between her and Warner Bros. Television that they would part ways.

It had also been speculated the Orange is the New Black' actress had decided to leave 'Batwoman because she was still in pain connected with the emergency surgery she underwent on two herniated discs.

However, a source insisted the star's decision ''had nothing to do with her health or injury.''

Ruby previously insisted quitting the show had been a ''very difficult'' decision.

She said: ''I have made the very difficult decision to not return to 'Batwoman' next season. This was not a decision I made lightly as I have the utmost respect for the cast, crew and everyone involved with the show in both Vancouver and in Los Angeles.

''I am beyond appreciative to Greg Berlanti, Sarah Schechter and Caroline Dries for not only giving me this incredible opportunity, but for welcoming me into the DC universe they have so beautifully created. Thank you Peter Roth and Mark Pedowitz and the teams at Warner Bros. and The CW who put so much into the show and always believed in me. Thank you to everyone who made season one a success - I am truly grateful.''