Duplicate results in an AWS Athena (Presto) DISTINCT SQL Query?

I have confirmed with the AWS team, that this was a known bug with AWS Athena at the time the question was asked. I'm not sure if this has been resolved.

When in doubt please use CTAS to remove any duplicates :

CREATE TABLE new_table
WITH (
      format = 'Parquet',
      parquet_compression = 'SNAPPY')
AS SELECT DISTINCT *
FROM old_table;

Reference: https://docs.aws.amazon.com/athena/latest/ug/ctas-examples.html