Various right-wing sources ranging from the New York Post to Fox News have reported that the top Hamas leaders are all billionaires.
Hamas leaders worth staggering $11B revel in luxury — while Gaza’s people suffer
or
Hamas bosses Khaled Mashaal and Ismail Haniyeh are worth an estimated $4 billion each, and political bureau leader Mousa Abu Marzouk is worth $3 billion.
Although left-wing [US] sources probably are not in love with Hamas either, I don't see them repeating those claims as readily, at least not in headlines.
So, what's the actual evidence that Hamas leaders are all billionaires?