Amid concern that Russia may also seek to influence European elections, the National Front has begun to play down its ties to Moscow. In February Saint Just said the party was reaching out to Russian banks for 25 million euros to bankroll its presidential campaign.

Unlike other candidates, Le Pen hasn’t disclosed her campaign’s funding or spending.

https://www.bloomberg.com/politics/articles/2016-12-22/le-pen-struggling-to-fund-french-race-after-russian-backer-fails

We will never see Trump's tax returns.