CNBC revealed on Wednesday that the Mueller team has been asking witnesses to hand over their personal phones and provide investigators access to their encrypted messaging programs such as WhatsApp, Confide, Signal and Dust as part of their investigation into whether the Trump campaign colluded with Russian operatives.
In an interview with CNBC on Thursday, Giuliani said he wouldn't agree to provide the president's personal devices unless certain preconditions were met beforehand.
"I wouldn't do it now. I wouldn't reject it out right either. I would ask for preconditions to be met. I would want to know why they need it," Giuliani said. "They would have to ask for specific conversations off of that phone because they are going to be listening to things they shouldn't be listening to. I'm talking about protecting his legal rights and confidential presidential conversations," he added.
He also noted that Mueller has not asked for the presidents phones and isn't convinced they will receive such a request.
Giuliani has famously called on Mueller to agree to a certain set of conditions when it comes to an interview with the president for the Special Counsel's Russia investigation. Those conditions include limiting the timing of the sit-down to two to three hours while also having the questions narrowed to topics focusing on collusion and obstruction.
A White House spokesperson did not return a request for comment. A spokesman for the Special Counsel declined to comment.
Former campaign chairman Paul Manafort has been accused by the Mueller investigation of tampering with witnesses through the same types of programs.
On Monday, the special counsel filed a claim that Manafort had tampered with witnesses after he was indicted in February for money laundering and illegally acting as a foreign agent.
For evidence, Mueller's deputy listed two apps, WhatsApp and Telegram, that they say Manafort used to contact the witnesses in his case.
Representatives from WhatsApp, Signal and Dust did not return requests for comment. A representative for Confide could not be reached.