Eight current and former officials of U.S. coal producer Drummond Co Inc...were called last week to testify before Colombian investigators about allegations the company supported far-right paramilitary death squads...

Prosecutors have investigated allegations for more than a decade that Drummond financed paramilitary groups involved in the 2001 assassination of two union leaders in northern Colombia.

Drummond and company officials were exonerated by U.S. courts in the case. In Colombia officials were also exonerated, but a contractor was sentenced to 38 years in prison for making payments to the paramilitaries...

The attorney general's office would not confirm whether this investigation relates to new allegations or if it is part of an open investigation into the previous charges...