'What is taking so long': Trump tries to undermine inspector general ahead of Clinton report
President of the United States of America, Donald Trump. (NATO photo)

President Donald Trump undermined the inspector general report his allies hope will justify his attacks on law enforcement and political rival Hillary Clinton.

Michael Horowitz, the inspector general for the Department of Justice, is expected to release a nearly 500-page report criticizing the handling of the Clinton email investigation by the federal agency and the FBI.

The president suggested in a Tuesday morning tweet that the investigation was tainted by politics.

"What is taking so long with the Inspector General’s Report on Crooked Hillary and Slippery James Comey," Trump tweeted. "Numerous delays. Hope Report is not being changed and made weaker! There are so many horrible things to tell, the public has the right to know. Transparency!"