TEHRAN, Young Journalists Club (YJC) -The Wall Street Journal said on Thursday the jury started its work several weeks ago. According to the paper, the probe is intensifying and could stretch for months.
Mueller is also reportedly investigating financial records of President Donald Trump’s associates.
The establishment of the grand jury will allow Mueller to subpoena officials and get sworn testimony which may lead to criminal indictments.
White House special counsel Ty Cobb claimed that he was unaware of the development.
“Grand jury matters are typically secret. The White House favors anything that accelerates the conclusion of his work fairly," Cobb said in a statement. "The White House is committed to fully cooperating with Mr. Mueller."
The grand jury is located in Washington, DC. It follows a separate grand jury previously convened in Alexandria, Virginia, by federal prosecutors probing Trump’s former national security adviser Michael Flynn.
The White House has maintained its belief that Trump is not likely the subject of an investigation.
“Former FBI Director Jim Comey said three times the president is not under investigation and we have no reason to believe that has changed,” said White House spokeswoman Sarah Huckabee Sanders when asked about the grand jury.