Hillary Clinton is reportedly poised to announce her candidacy for the Democratic presidential nomination this weekend. The move comes as a new investigation has revealed Clinton’s close ties to a Canadian oil company with a history of alleged violence in Colombia. The International Business Times reports while Clinton was secretary of state she backed a Colombian free trade pact she had previously opposed over concerns about labor rights, after the founder of oil giant Pacific Rubiales pledged millions of dollars to the Clinton Foundation. The founder, Frank Giustra, now serves on the Clinton Foundation’s board. Labor leaders say Clinton ignored accounts of attacks on union organizers in Colombia, instead backing the trade pact which benefited Giustra and other foreign investors.