A photograph of Princess Diana reclining in bed with a previously unknown man –before her marriage to Prince Charles – will be sold at auction in America later this year, The Telegraph reveals. The identity of that man in the photograph has now been uncovered, however and is confirmed to be Adam Russell, the great-grandson of the former Prime Minister Stanley Baldwin.

Diana and Adam look to be fairly intimate in the photograph but an interview with the royal biographer Andrew Morton, for ITV News, reveals that although Adam was smitten with the future princess, nothing actually happened between them. The photograph was taken on a ski trip and both Diana and Adam were relaxing together after both being injured. “They kept each other company while the others went skiing and at the end of the holiday Adam was somewhat smitten, but absolutely nothing happened,” Morton told ITV. “He left unspoken the fact that he hoped the friendship between himself and Diana could be renewed and developed upon his return. When he arrived home a year later it was too late. A friend told him: 'You’ve only got one rival - the Prince of Wales.’” It is understood that Mr Russell is now a deer farmer, living in Dorset.

The picture was originally sold to the Daily Mirror in 1981, two days after Diana’s engagement to Prince Charles was announced. However, the publication’s editors decided against using it and the instruction “not to be published” is scrawled across it.