The Champions (1968)

Craig Stirling, Sharron Macready, and Richard Barrett were agents for Nemesis, an international intelligence organisation based in Geneva. Their first mission as a team: investigate some potentially lethal experiments in Communist China, but as they were escaping, their plane was damaged, and crashed into a remote part of the Himalayas. When they were rescued by members an unknown society, they came away with superhuman powers; telepathy, superior strength, memory, etc. They returned to the outside world as "Champions of Law, Order, and Justice."