The Alabama Attorney General's corruption unit -- the same group that just took down former Alabama House Speaker Mike Hubbard -- has opened an investigation in Birmingham.

The unit this week asked for and received permission to empanel a special grand jury -- the type used to investigate issues expected to take longer than a typical grand jury would, said Jefferson County Presiding Judge Joseph Boohaker, who signed the order.

The grand jury will convene October 17th, and can continue for months.

Boohaker said he could not talk about the nature of the grand jury's investigation, other than to confirm the document seeking to empanel the jury was requested by the attorney general's special corruption unit.

He said Matt Hart - the lead prosecutor in the Hubbard case and many other corruption prosecutions - came to his office personally to make the request. The document signed by Boohaker did not state a specific area of investigation.

Prosecutor Matt Hart questions witness Minda Riley Campbell during Alabama House Speaker Mike Hubbard's trial, Ala. (Todd J. Van Emst/Opelika-Auburn News via AP, Pool)

Some close to the Birmingham Water Works Board in recent weeks have said investigators from the state have begun to ask questions about operations there.

Questions have arisen about contracts at the water board, including a contract with Reuben Russell, who was awarded an engineering contract this summer despite having no engineering license nor engineers on staff. Russell had failed to provide even basic information to water works staff attempting to conduct due diligence, but he has been heartily supported by a majority of the board.

Russell this week terminated his contract with the water works. The board was notified of the decision today.

Russell, in an email to AL.com, said he terminated the contract on his own after weeks of controversy. He said it had nothing to do with the investigation.

"I took this action in the best interest of my company. And I took this step with no knowledge that the Alabama Attorney General's Office has, according to media reports, begun an investigation of the water board," he wrote. "I was not asked by anyone to take this step."

Water Works General Manager Mac Underwood said "the only state agency to contact BWWB is the Alabama State Board of Licensure for Professional Engineers and Land Surveyors," who questioned the Russell contract.

But questions about the Birmingham Water Works Board do not limit any investigation to the water works itself. The board has been the epicenter of political struggles over power and contracts for years, and that has only intensified in the last year.

The Birmingham City Council appoints members to the board, and several have been awash in criticism from those who claim they have used that appointing authority to help friends and associates obtain contracts with the board.

Mike Lewis, spokesman for the Attorney General Luther Strange, said "the Attorney General's Office is unable to comment."

Corrected 2:05 p.m. Sept. 15 to indicate Reuben Russell terminated the contract. Russell quotes added 4:31.