Like emails, handwritten notes or transcribed Oval Office conversations, the @realdonaldtrump account gives investigators a detailed timeline of Trump’s thoughts and opinions – including where they might differ from official accounts – and can also be used to establish intent, which can be critical in a criminal investigation.

Trump is not a target of the FBI or congressional probes, but his tweets could all be used by investigators as they seek to establish whether the president and his associates are being truthful in the explanations they give under oath about the nature of contacts between the Trump campaign and Russian officials. Trump’s tweets could ultimately cause problems for the people around Trump, including aides who sent messages under Trump’s account.

“They’re a gold mine,” said Peter Zeidenberg, who served on the Justice Department’s special prosecution team during the George W. Bush-era Valerie Plame Wilson investigation and now works as a partner at Arent Fox. “They help paint a picture.”

Trump’s attorneys have reportedly been trying to vet his tweets as the Russia probe gains steam, an attempt to harness the president’s uninhibited stream of political and policy punditry, biting put downs and other random asides that have upended all historic norms of White House communication.