LONDON—Michael Jackson looked in perfect health and gave an electrifying performance two days before his death during rehearsals for his planned comeback concerts, a photographer who took pictures of the rehearsals said Tuesday.

“Michael was back—that’s all I could say,” said Kevin Mazur, who was documenting the rehearsals for the tour book. “He was very upbeat, very happy, having a good time with the dancers. The performance was amazing.”

Jackson’s run of 50 shows was due to start at London’s O2 Arena in July. “It was the same old Michael I had been photographing for 30 years and I was so excited for the O2 arena show,” the American photographer told The Associated press by phone from Barcelona, Spain. “That day, after rehearsals, I was like I am bringing my kids to the O2 arena because they have got to see this.”

In May, Jackson’s representatives announced that he would postpone several of the shows, moving some of those scheduled in July to March 2010, fueling speculation that the King of Pop was suffering from health ailments. But Mazur, who saw the star perform in Los Angeles on June 23, two days before his death, said Jackson looked in perfect health.