US Justice Department has escalated its review into the origins of the collusion between Russia and the Trump administration to a criminal investigation, The New York Times reported, citing two sources familiar with the matter.
It is unclear what potential crime Durham is investigating, as well as when the criminal investigation was prompted.
The Justice Department declined to comment, the Times says.
US President Donald Trump has repeatedly denied the allegations of conspiring with the Russian government (as has the Kremlin), and US Special Counsel Robert Mueller said in his report that he had not found enough evidence to prove the collusion took place. Following the publication of the report, US Attorney General William Barr appointed Durham to lead the review the origins of the "Russian collusion" probe.
Mueller's probe was initiated by the Federal Bureau of Investigation (FBI) in 2016, after they received information that a Trump campaign staffer was approached with an offer of hacked emails of election rival Hillary Clinton. Durham's review will seek to determine whether the FBI were tipped by US intelligence agencies (the CIA in particular) and whether their methods of information gathering were lawful, The New York Times says.