The special counsel investigation led by Robert Mueller is increasingly looking into President Trump's finances and the financial ties of many of his associates.

People "familiar with the investigation" told CNN that investigators see the financial avenues as a more fertile path than investigating the sometimes-grey areas of collusion and obstruction of justice.

The report comes close on the heels of another revelation that Mueller has impaneled a grand jury in Washington, a sign that the special counsel is ramping up its operation.

President Trump warned investigators about digging into his and his associates' financials, and said that was a red line that shouldn't be crossed. The "red line" language, however, was that of the interviewer, and Trump only affirmed that he agreed with that characterization when asked.

But days after the president made those remarks to the New York Times, numerous reports hit media outlets alleging that the president and his team were digging into the credibility and possible conflicts of interest of the team Mueller had assembled, and that Trump was investigating possible ways of dismissing Mueller.

Jay Sekulow, the president's outside counsel, said, "President's outside counsel has not received any requests for documentation or information about this. Any inquiry from the special counsel that goes beyond the mandate specified in the appointment we would object to."

Other sources said some of the potential financial crimes being looked at by investigators have nothing to do with the 2016 campaign.

"Even investigative leads that have nothing to do with Russia but involve Trump associates are being referred to the special counsel to encourage subjects of the investigation to cooperate, according to two law enforcement sources," CNN said.

In the same New York Times interview in which a financial "red line" was discussed, Trump said, "But I have no income from Russia. I don't do business with Russia."

Investigating Trump's finances would satisfy many Democrats like Oregon Senator Ron Wyden, who has been trying to pressure some senate committees to request financials from the president. On the same day that former FBI Director James Comey testified about his conversations with President Trump, Wyden said obstruction of justice was a "technical issue."

"Today, for example, didn't even get into the area I have focused on, the ‘follow the money' issues," Wyden said. "Money laundering, property transfers, shell corporations, that sort of thing."