'90 Day Fiance' Paul Staehle's Family Worried He's Lost in Brazil

Paul Staehle's family is worried sick about him ... because he's a world away over in the Amazon and now appears to be lost in Brazil.

The "90 Day Fiancé" star's mom, Edna, tells TMZ ... Paul has been traveling in Brazil since the end of July, but on Thursday morning he sent his family some alarming texts.

We're told Paul told his mom he needed her help and was lost in the South American country ... telling her needed a boat and giving her contact info for a few folks he said might be able to help him get out of his situation.

It's pretty alarming on its face, and Edna says Paul has since gone radio silent ... she can't get in contact with him and it appears his phone is off, lost signal or is out of battery.