How did President Trump come up with $10 million Russia probe price tag?

Washington -- Wedged in the middle of a Tuesday morning tweet by President Donald Trump bashing the news media and boasting about his poll numbers was a complaint about the "$10,000,000 Russia Witch Hunt."

So where does that "$10,000,000" number come from? The only budget figures for the special counsel released so far were in the statement of expenditures that the Justice Department put out in December.

That statement used broad numbers to show that the special counsel spent $6.7 million on staff and expenses since its creation on May 17, 2017, through September 2017, the end of the 2017 fiscal year. Justice Department officials say the next report, expected to be released in coming weeks, will show expenditures from October through March.

The Acting Attorney General approves the special counsel's budget but Justice Department regulations make clear that "a special counsel shall be provided all appropriate resources by the Department of Justice."

Sources familiar with the matter told ABC News the $10 million figure comes from a placeholder number in the FY 2019 Department of Justice budget request. The actual amount is $10,400,000 for the line item titled "INDEPENDENT COUNSEL (PERMANENT INDEFINITE)." That number, however, is not an indication of what the special counsel has spent or is expected to spend.

Based on the totals in the first expenditure report, it is quite possible or even likely that the total expenses for the Mueller probe will exceed $10 million. As the investigation nears the one year mark, it remains unclear when the probe will be wrapped up.