A former US Marine, who once stunned the world with his extraordinary tale of stumbling across a clandestine military rendezvous with an otherworldly spacecraft, says he is now living in fear.

Michael Herrera, from Denver, believes sinister forces are determined to silence him and cover up the Pentagon's UFO secrets.

He was a 20-year-old rifleman sent on a Navy humanitarian mission during the 2009 Sumatra earthquake and tsunami that devastated the region.

Around October 8 he and five marines were dropped off at a clearing in the north eastern part of Padang City and hiked 900ft up a ridge to take their positions for the incoming supply drop, Michael said.

It was then he spotted a strange object in the jungle on the other side of the hill.

To read more, click here.