New Delhi, May 17 -- A former CIA-funded researcher has triggered fresh controversy after claiming the United States may have recovered four distinct alien species from crashed UFOs.

Hal Puthoff, a physicist and former adviser to the US government's Advanced Aerospace Weapon System Applications Program, made the remarks during an appearance on the The Diary of a CEO podcast hosted by Steven Bartlett alongside filmmaker Dan Farah.

"People who have been involved in recoveries have said there are at least four types. Four separate types," Puthoff said during the interview.

"Now I have not had direct access to that but I believe the people who I talked to - four separate types of life," he added.

The comments have reignited long-running d...