Special counsel Robert Mueller's investigation tops $5 million Investigations of this type take years and cost tens of millions of dollars.

 -- Special Counsel Robert Mueller's investigation into the Russian government's efforts to interfere with the 2016 election has cost more than $5 million, ABC News has learned.

Those expenses include money for a staff of more than 16 attorneys, dozens of FBI agents, support staff, travel and office supplies.

A more detailed breakdown of those expenditures is expected to be released in the coming days. Investigations of this nature can take years to resolve and run into the tens of millions of dollars.

The Ken Starr probe into Whitewater — the investigation into Bill and Hillary Clinton and associates' real estate dealings — and other matters saw more than $70 million in expenditures and went on for more than six years.

Mueller, appointed in May, has already secured an indictment of Trump campaign chair Paul Manafort and top campaign lieutenant Rick Gates as well as a guilty plea against Trump campaign foreign policy adviser George Papadopoulos.

Former Trump National Security Adviser, Michael Flynn, now finds himself in the crosshairs of the investigation and could face charges.