Washington, May 18: The US justice department has appointed a former FBI director as a special counsel to oversee an investigation into Russian meddling in the presidential election, dramatically raising the legal and political stakes in an affair that has threatened to engulf Donald Trump's four-month-old presidency.
The decision to place the inquiry in the hands of Robert Mueller was a political blow to Trump and indicates how serious the allegations levelled against the President have become. The Republican senator John McCain said that Trump's troubles had reached "Watergate size and scale".
The decision by the deputy attorney-general, Rod J. Rosenstein, came after a cascade of damaging developments for Trump in recent days, including his abrupt dismissal of the FBI director, James B. Comey, and the subsequent disclosure that Trump had asked Comey to drop the investigation of his former national security adviser, Michael T. Flynn.
Trump decried the appointment of the special counsel as "the single greatest witch-hunt" in US history.
Mueller's role will be similar to that of the special prosecutors who played key parts in the Watergate scandal, which toppled Richard Nixon, and the Monica Lewinsky affair, which led to Bill Clinton's impeachment. However, a special counsel has less autonomy than a special prosecutor, a role phased out in 1999.
Mueller has been authorised to investigate "any links and/or co-ordination between the Russian government and individuals associated with the (Trump) campaign" and "any matters that arose or may arise" from the inquiry.
Mueller is a former federal prosecutor with an unblemished reputation and has worked with Comey.