Britain's Got Talent winner Pudsey the dog has died, ITV has confirmed.
The border collie, bichon frise and Chinese crested cross won the contest in 2012 with owner Ashleigh Butler.
The pair became famous for their dance routine to the Mission Impossible theme, and were the first dog act to win the competition.
Paying tribute to Pudsey on Friday, Ashleigh described him as a "beautiful boy" who had changed her life.
A post on the Britain's Got Talent Twitter feed said: "We are saddened to hear that today we lost Pudsey, a most marvellous winner. Our thoughts are with Ashleigh."
Ashleigh said 11-year-old Pudsey was put down on Thursday after a short battle against leukaemia.
"I had to make the hardest decision of my life to let my beautiful boy go to sleep at the age of 11," she said.
"From the minute he was born he brought nothing but joy to me, and as a winner of BGT millions of others who adored him too.
"No words can express just how much I will miss him.
"He changed my life and I have so many wonderful memories of our time together. He will always be in my heart."
Pudsey and Ashleigh, from Wellingborough in Northamptonshire, had worked together for 11 years.
In October 2012, a book titled Pudsey: My Autobidography, was released, chronicling the pet's rise to fame.
He hit the big screen in 2014, taking the leading role in his own movie, Pudsey The Dog: The Movie.
The pair also travelled to America following their big win, where they performed on America's Got Talent and appeared on The Tonight Show with Jay Leno.
Tributes began to pour in within minutes of Britain's Got Talent sharing news of his death, with fans saying they were "heartbroken" and sending wishes to his family.
Britain's Got Talent judge David Walliams took to Twitter to pay tribute, writing: "Farewell to a very special dog that the nation fell in love with".
Fan Jennifer Wood tweeted: "Actual just started crying reading and article about Pudsey the dog dying...too sad".