Twitter and Facebook are alight with rumours that Elisabeth Sladen has passed away.

The Doctor Who star, who is best known as Sarah Jane Smith and also stars in the spin off CBBC show The Sarah Jane Adventures, is said to have passed away earlier today.

Sources say the 63 year old star died because of complications arising from a battle with cancer.

The actress was a regular on BBC’s Doctor Who with both Jon Pertwee and Tom Baker, and has reprised her role many times. She first joined the sci-fi show in 1973 and stayed on for three and a half seasons, before leaving in 1976.

After numerous appearances through the 80s and 90s, Elisabeth returned in 2006, acting opposite the then Doctor David Tennant in an episode titled “School Reunion”.

Following her successful appearance in the series, Sladen was then asked to front The Sarah Jane Adventures, written by Russell. T Davies for CBBC. The show ran for four series, with a fifth scheduled to air later in 2011.

Sladen was amazing on screen and a real fan favourite, she was welcomed back for two episodes of Doctor Who’s 2008 series finale “The Stolen Earth” and “Journey’s End” and was credited in the title sequence of both episodes. She also had a cameo in the concluding part of The End of Time, Tennant’s last episode as the Doctor. This was her last appearance on the show.

This has not yet been confirmed, so more news to follow.