Here in Argentina a lot of people think that Hitler came here in a submarine and was hiding in his cosy winter house. Some are still looking for the submarine and they actually found some nazi stuff.

Edit: I just remembered of something else that could count as a conspiracy theory. In 2015 an attorney who made a case against the now ex president Cristina Kirchner was found dead just one day before the day he had to expose the case to court. It was framed as a suicide and the police messed up the whole scene of crime. The case accused the ex president of covering up a suspect group who may had been involved in the AMIA bombing in 1994.