Scientist Sir Charles Shults III discussed water activity and fossils on Mars, and possible manipulation of Mars photos by NASA.
Shults believes Mars was once an ocean covered planet filled with (non-intelligent) life, and stated emphatically, "It is very clear there is life on Mars; there was life on Mars." As evidence, he cited his recent discovery of Sea Urchin and other ancient marine fossils, water erosion, and geyser activity on Mars. According to Shults, NASA and JPL employees have told him privately that his findings are correct.
He also alleges that NASA has tampered with photos taken by Mars Exploration Rover Opportunity. Specifically, he referred to Sol 167 and 168. Shultz said NASA has been caught modifying images in the past (article), so he has "almost no confidence in anything presented by NASA" and is convinced they are currently censoring anything that proves life on Mars.