US President Donald Trump on Friday denied that he knew in advance about the meeting his son had with a Russian lawyer ahead of the 2016 US presidential election. The President reacted via Twitter to a CNN report that Trump's one-time personal attorney, Michael Cohen, claimed the real estate mogul approved Donald Trump Jr.'s plan to meet with the attorney, who ostensibly had damaging information about Democratic presidential candidate Hillary Clinton. "I did NOT know of the meeting with my son, Don jr.," Trump said in the first of a sequence of tweets. "Sounds to me like someone is trying to make up stories in order to get himself out of an unrelated jam (Taxi cabs maybe?)." The President was alluding to Cohen, who faces a federal criminal investigation over his personal business dealings involving the taxi industry in New York, Efe reported. Prosecutors are also looking at Cohen's efforts to quash negative news about Trump during the 2016 campaign, which are of interest to Robert Mueller, the special counsel heading the probe into alleged Russian meddling in the election and possible collusion between the Kremlin and the Trump campaign. Cohen recently turned to prominent attorney and lobbyist Lanny Davis, a long-time associate of Bill and Hillary Clinton, to represent him. Cohen even retained Bill and Crooked Hillary's lawyer," Trump wrote on Twitter. "Gee, I wonder if they helped him make the choice!" Friday's tweet storm from the President included another denunciation of Mueller's investigation as "the rigged Witch Hunt".