US President Donald Trump has sparked controversy with tweets criticizing Democratic senator Al Franken for sexual abuse while keeping mum on similar allegations against his party fellow Roy Moore, a nominee for the upcoming Senate election in Alabama.

"The Al Frankenstein [Franken] picture is really bad, speaks a thousand words," Donald Trump wrote referring to a picture of Al Franken, who has recently been accused of sexual misconduct by journalist Leeann Tweeden.

The photo Trump mentioned was posted by Tweeden when she decided to tell her story about Franken. The picture shows Franken apparently fondling Tweeden's breasts while she slept.

?Trump then referred to a vulgar joke about rape Franken reportedly made when he was a writer with "Saturday Night Live" in the 1990s. Franken offered an idea for a sketch in which he would give reporter Lesley Stahl pills and "rape her" in the closet.