In 2002, the families of three deceased Colombian labour leaders and the union they belonged to, Sintramienergética, filed suit against Drummond Company, Inc. and its wholly-owned subsidiary Drummond Ltd. in US federal court. The plaintiffs alleged that Drummond hired Colombian paramilitaries to kill and torture the three labour leaders in 2001. Sintramienergética represents workers at Drummond’s coal mining operations in Colombia. The case was brought under the US Alien Tort Claims Act (ATCA), US Torture Victim Protection Act and Alabama state law. Drummond sought dismissal of the case, which the court granted as to the state law claims and one of the ATCA claims in 2003. The court declined to dismiss the ATCA claims for extrajudicial killing and for denial of rights to associate and organise. In March 2007, the court ruled that the case against Drummond Ltd. (the subsidiary) would go to trial, but dismissed the case against Drummond Company (the parent company). In June of 2007, the district court judge dismissed the wrongful death claims, but the judge allowed the plaintiffs’ war crimes allegations under ATCA (summary execution) to stand. The trial was held in July 2007. The jury acquitted Drummond finding that the company was not liable for the deaths of the three murdered labour leaders. On 11 December 2007, the plaintiffs filed their opening brief to appeal the lower court's verdict with the US Court of Appeals for the 11th Circuit.
In March 2009, the children of three slain Colombian union leaders filed a new lawsuit in US federal court against Drummond alleging the company's complicity in the killings. Another lawsuit was filed in US federal court against Drummond in May 2009 alleging that the company had made payments to the paramilitary group United Self-Defense Forces of Colombia (known by its Spanish acronym AUC) to kill labour leaders. Drummond has denied these allegations. While a lower court dismissed the lawsuit brought by the union leaders' children, on 3 February 2011 the federal court of appeals reversed this dismissal and remanded the case to the lower court. The court of appeals found that the children did have standing to pursue their claims against Drummond and remanded their previously dismissed claims under the Alien Tort Claims Act and the Torture Victim Protection Act for further proceedings at the trial court level. On 25 July 2013 the district court judge dismissed the case against Drummond finding that the court no longer had jurisdiction to hear the case, citing the US Supreme Court's decision in Kiobel v. Shell.
In February 2013 a former contractor for Drummond was sentenced by a Colombian court to 38 years in prison for organizing the killing of two labour leaders in 2001. The judge ordered prosecutors to investigate Drummond’s president and several former employees to determine whether they had a role in the killings.