Washington, May 11 (IANS): The chairman of a US Congressional committee has issued subpoenas for President Donald Trump's tax returns, the committee told CNN.

House Ways and Means Committee Chairman Richard Neal on Friday sent the subpoenas to both Internal Revenue Service (IRS) Commissioner Charles Rettig and Treasury Secretary Steve Mnuchin.

A Treasury spokesman confirmed to CNN it has received Neal's subpoena request.

Neal, who has unilateral subpoena power, took the step days after the Treasury Department formally denied his request for six years of the President's personal and business tax returns earlier this week.

While Neal did not need a subpoena to eventually move to court, he issued the subpoenas on the advice of House counsel whom he consulted throughout the process about how to build the strongest legal case.

Unlike other requests for information coming from House Democrats, Neal is relying on a decades-old tax statute -- 6103 -- that says that the House Ways and Means chairman, Senate Finance Committee chairman or chief of staff of the Joint Committee on Taxation can request any individual's tax information in the course of their legislative business.

Neal's move is expected to eventually be followed by action to go to court, a process that could take months or even years.

If the Treasury Department or IRS defy the subpoenas, the House counsel would ask the speaker of the House to authorise court action.

Then, the speaker has the options of either having a full House vote or what is more likely, ask the Bipartisan Legal Advisory Group to approve legal action.

The group is made up of three Democrats and two Republicans meaning that Democrats can authorise any legal action they want through a vote of the group.