The investigation into Russian intervention in the US presidential election last year and possible collusion with the Trump campaign has taken a far more serious turn after it emerged that Special Counsel Robert Mueller has convened a grand jury. The establishment of a grand jury suggests that the investigation will now adopt a tough approach and spells further trouble [VIDEO] for United States President Donald Trump, who has called the whole thing a 'witch hunt' in the past.

A massive step

The investigation could prove to be one of the most important in the history of the United States and the latest development certainly indicates that Special Counsel Robert Mueller is not going to leave any stone unturned in order to unearth the full extent of Russian intervention in last year's election.

The grand jury will give the investigators greater legal powers since it can force anyone to testify by way of subpoenas and it is a truly massive development in the Russian investigation saga.

Over the past two months or so, the investigation has made some headway and has looked into business transactions of the President's son-in law and close advisor Jared Kushner. Additionally, there have been reports that Donald Trump's own business transactions with Russians could also be under the scanner. Although the grand jury will not disclose what it will look in to, it is understood that it will investigate whether people connected to the Trump campaign were in cahoots with the Russians as regards the release of sensitive information about Hillary Clinton's campaign.

Trump reacts accordingly

The President, however, is known to react to such developments in his own inimitable style [VIDEO]and he did so during a rally at Huntington, West Virginia.

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During the rally, Trump called the allegations a hoax and went on to state that it damaged the prestige of the United States. He also dismissed all the allegations about Russian intervention into the election and possibility that they helped his campaign. Trump said, "Most people know there were no Russians in our campaign. There never were. We didn't win because of Russia, we won because of you."

White House special counsel Ty Cobb, who had been appointed specifically for the purpose of taking care of responses to developments in the Russian investigations stated that the White House will co-operate fully with the investigation. He also went on to state that the White House will be in favor of any measure that "that accelerates the conclusion of [Mr. Mueller's] work fairly."