Killing WikiLeaks founder Julian Assange with a drone strike would violate international law, according to a United Nations envoy and expert on summary executions.

The website True Pundit on Monday reported that Hillary Clinton had raised the possibility of using a drone strike against Assange during her term as secretary of state, citing unnamed State Department sources. Clinton’s campaign manager, Robby Mook, said on Monday that he was “reticent to comment” on the veracity of the report.