Freddie Mercury's final poignant screen appearance will be shown tonight in a documentary which has uncovered unseen footage from Queen's most famous videos.

The BBC Two film, Queen: Days Of Our Lives, includes footage of the flamboyant singer, painfully thin from the effects of the HIV virus which would kill him just months later, determined to complete his final video shoot.

Mercury is shown applying make-up and checking his image and performance on screen monitors before stepping carefully onto the stage and delivering a solo performance of the band's 1991 single "These Are The Days Of Our Lives". He exits the frame after whispering the final line "I still love you". His death from Aids-related pneumonia, at the age of 45, was announced in November 1991, one day after he issued a statement saying he was suffering from the disease.

The footage emerged during a five-year trawl through the Queen archives by Rhys Thomas, the comedy actor, who co-produced the documentary. Queen invented the rock-video genre with the performance film accompanying "Bohemian Rhapsody" in 1975.

The documentary shows the band sitting in a space-age car having a cigarette in between takes for the Metropolis-influenced video for "Radio Ga Ga" in 1984. The documentary also follows the row over the band's controversial video for "I Want To Break Free". Mercury's open display of transvestism in the Coronation Street-inspired video led to MTV banning the band from its US network.

Thomas said: "The footage of Freddie in his final video is shocking. He is so frail, he needs two hands to hold a champagne glass. But he knows he is being filmed and wants to show people what he was going through."

Brian May, Queen's guitarist, said of Mercury's final scenes: "At this time, Freddie's becoming weakened by this horrible disease, but he'd throw a couple of vodkas down and prop himself up on the mixing desk and go for it.