U.S. President Donald Trump appeared to acknowledge in a post on Twitter that he is "being investigated" for firing FBI Director James Comey, adding the assertion that the probe is being conducted by the man who told him to fire Comey.
In a tweet on June 16, the president wrote: "I am being investigated for firing the FBI Director by the man who told me to fire the FBI Director! Witch Hunt."
It was unclear whether Trump had received official notification that he was under investigation or was merely responding to media reports.
Citing unnamed sources, The Washington Post this week reported that special counsel Robert Mueller has widened his current investigation into Russian meddling in the 2016 U.S presidential election to include the possibility that Trump attempted to obstruct justice by firing Comey.
Mueller's initial investigation was probing the possibility that Trump surrogates colluded with the Russians to influence the election in order to boost Trump's chances against Democratic rival and former Secretary of State Hillary Clinton.
As head of the FBI, Comey had been leading the investigation until he was fired by Trump on May 9.
It also was not clear if the president was referring specifically to Deputy Attorney General Rod Rosenstein, who is now overseeing the Russia investigations because Attorney General Jeff Sessions recused himself, citing the fact that he had been a member of Trump's transition team and had had contacts with Russian officials.
Rosenstein submitted a widely circulated memo to the president last month raising concerns over Comey's performance that Trump cited in his letter dismissing Comey. Trump later asserted that he had already made the decision himself to fire Comey before Rosenstein's memo.
After Comey's firing, Rosenstein appointed Mueller to lead an independent investigation on matters involving Russia's alleged meddling and related matters.
The U.S. television network ABC, citing unnamed sources, reported that Rosenstein had informed Associate Attorney General Rachel Brand that he may have to recuse himself from the Russia investigations as well, because of his memo to Trump about Comey.
Trump has denied any involvement with the Russians during the campaign and has called media reports of collusion a "hoax" and a "phony story."
In another tweet on June 16, Trump wrote: "After 7 months of investigations & committee hearings about my 'collusion with the Russians,' nobody has been able to show any proof. Sad!"
Concerns that Trump may have tried to obstruct justice are based partly on testimony from Comey before a Senate panel on June 8.
Comey testified that he believed his dismissal was an attempt to exert influence on the investigation into alleged Russian interference and possible collusion.
Comey has also said Trump asked him to drop an investigation into ties between Michael Flynn, who advised Trump during the campaign and briefly served as national security adviser after Trump's inauguration, and Russian officials.
In late May, Trump hired longtime legal adviser Marc Kasowitz to serve as his attorney in Russia-related matters.
On June 15, Vice President Mike Pence, who headed the Trump transition team, confirmed that he, too, had hired a private lawyer to represent his interests in the probe.
Meanwhile, The New York Times reported on June 16 that the general counsel's office of Trump's transition team has ordered staff to preserve all materials relating to Russia or Ukraine, including any possible travel documents.
In a related matter, The Washington Post reported that Mueller is also looking into the finances and business dealings of presidential adviser Jared Kushner, citing officials familiar with the matter.
Kushner, a real estate entrepreneur who is married to Trump's daughter Ivanka, came under scrutiny after it was reported he met with Russian Ambassador Sergei Kislyak and with a Russian banker during the transition period.