Bangladesh, Aug. 6 -- Freshly released documents from the Trump administration have reignited political and legal debate over the origins and conduct of the FBIs investigation into alleged links between Donald Trump and Russia, with officials arguing that federal investigators launched a new inquiry despite possessing information that had already undermined key allegations of collusion.

The disclosures center on a previously undisclosed FBI subcomponent investigation known internally as “Oxferd Comma,” which was opened on May 16, 2017, one day before the appointment of Special Counsel Robert Mueller. According to administration officials, the investigation was based on the premise that then-President Donald Trump may have bee...