"It's just flat-out untrue", Mr Giuliani, the former mayor of New York City, said on "Fox News Sunday" about the claims.
In a later interview on CNN, Giuliani again said that collusion was not a crime.
That wasn't the only wild assertion Giuliani made on his tour of cable news stations Monday morning.
Giuliani said Monday that the Trump team actually knows of "183 recordings" from Cohen, but many of them involved people having nothing to do with Trump. There is no collusion, and even if there was, it's not a crime. "The president didn't hack", Giuliani said on CNN.
Donald Trump has said "collusion is not a crime" ahead of the first trial in the Russian Federation investigation.
For almost a year now, political pundits, Trump lawyers, and Americans from every walk of life have been trying to pinpoint how much longer Robert Mueller and the Special Counsel's office would take before issuing a final report on possible crimes committed by the Trump campaign. "He didn't pay for the hacking".
Pointing to Manafort's short stint as Trump's campaign manager, Giuliani added, "Four months, they're not going to be colluding with Russia, which I don't even know if that's a crime, colluding about Russians".
"Note to Giuliani: Look it up-Colluding to violate the law is conspiracy", Sen.
"Obstructing Justice also is criminal", Blumenthal wrote.
While the cringing Wormtongue could also be used to describe many in the current administration, Gollum seems like the best fit for Trump's current counsel. "Bombast & bullying won't make it (or him) go away".
Giuliani said Mueller is "not entitled" to ask any questions about obstruction of justice, since the president was authorized under the Constitution to remove FBI Director James Comey. Richard J. Durbin (D-Ill.) expressed exasperation with Giuliani's media interviews.
He said Trump's legal team presented its offer for limited questioning of the president to Mueller's team 10 days ago but has not heard back.
In particular, prosecutors say they will introduce evidence that a chairman of one of the banks allowed Manafort to file inaccurate loan information in exchange for a role on the Republican campaign and the promise of a job in the Trump administration that never materialised.