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Late on Tuesday night, a watchdog group released a trove of documents from the White House Office of Management and Budget related to President Donald Trump’s hold on military aid to Ukraine. The disclosure of the material, obtained by the nonprofit American Oversight, came just hours after the Senate voted along party lines not to subpoena OMB documents or require testimony from two OMB officials, Robert Blair and Michael Duffey, in Trump’s impeachment trial. The president’s decision to block aid that had been appropriated by Congress is at the center of the Ukraine scandal.

The documents American Oversight released is composed largely of email traffic from Duffey, a political appointee who played a key role in executing the hold. The material reveals a flurry of activity by Duffey and a group of OMB employees related to the Ukraine aid just before Trump’s July 25 call with Ukrainian President Volodymyr Zelensky. Just after the call, the emails show, Duffey met with OMB General Counsel Mark Paoletta about the “Ukraine topic.”

The emails also shed new light on administration efforts to release the hold after it came to light that Trump had pressured Ukraine for investigations that could benefit him politically.

The material OMB handed over, however, is heavily redacted, leaving its import not entirely clear. The Senate could presumably obtain the unredacted versions from OMB. Republicans just have to agree to ask.