Benedict Cumberbatch is backing a petition for the British government to pardon men who have been punished for being gay.
The Emmy Award winner - who is engaged to theatre director Sophie Hunter - has joined the campaign along with 40,000 others who are calling for the authorities to apologise for convicting more than 49,000 homosexuals for gross indecency in the past, including 15,000 men who are still alive.
The letter, signed by the Oscar nominee, states: "The UK's homophobic laws made the lives of generations of gay and bisexual men intolerable."
As well as the 'Sherlock' star, the Duke and Duchess of Cambridge, Catherine and William, are among other high-profile individuals to have signed the petition.
It continues: "It is up to young leaders of today including the Duke and Duchess of Cambridge to acknowledge this mark on our history and not allow it to stand."
Last year, the 38-year-old actor starred as codebreaker Alan Turing in 'The Imitation Game' who cracked the Nazi Enigma code, a breakthrough which was praised as a turning point for the allies in World War II.
However, the man who Benedict played was punished for being gay following the War, and was chemically castrated in 1952, before committing suicide two years later.
The letter adds: "We call upon Her Majesty's government to begin a discussion about the possibility of pardoning all the men, alive or deceased, who like Alan Turing were convicted."