Martina Navratilova said she is "not done yet" after it was confirmed she had been diagnosed with throat and breast cancer.

Navratilova is one of the most decorated tennis players of all time, having won 18 grand slam singles titles between 1978 and 1990.

She successfully underwent treatment for breast cancer in 2010, but it has been revealed she is once again battling the illness.

A representative described Navratilova's prognosis as "good", and the 66-year-old said the disease was "serious but still fixable".

Navratilova has pledged to fight, posting on Twitter: "Needless to say my phone and Twitter are both blowing up.

"I will say again – thank you all for your support and I am not done yet."

The Czech also received support from Billie Jean King, who tweeted: "Martina is as brave as she is strong. She has fought this battle before, and she is in our thoughts and prayers."