United Kingdom, Aug. 21 -- Wladimir Klitschko has marked Hayden Panettiere's birthday by celebrating "her life".

The Hollywood star passed away on August 16, aged 36, and Wladimir, her former partner, has taken to social media to thank fans for their recent show of support.

Wladimir, 50 - who has an 11-year-old daughter called Kaya with the actress - wrote on Instagram: "Today is Hayden's birthday. Instead of celebrating the way we had planned, today we celebrate her life, her spirit, and the love she brought into this world.

"I want to thank all of Hayden's fans, friends, and everyone who has reached out for the incredible outpouring of love and support. At a time filled with so much sadness, your kindness has reminded me that there i...