PROVIDENCE — For the fourth time since 2004, the Ethics Commission has ordered a formal investigation into whether Governor Carcieri has violated state ethics rules.

The commission voted yesterday to investigate whether Carcieri broke the anti-nepotism provisions of the state Code of Ethics by hiring a relative and former campaign worker for a state job in 2002.

The governor has already settled three other, unrelated ethics cases by paying fines.

The commission acted in closed session yesterday after Carcieri’s lawyers attempted unsuccessfully to remove one commission member, Ross E. Cheit, from the case. Cheit had objected to the governor’s handling of the case at an earlier meeting.

Chairwoman Barbara R. Binder said the commission concluded that if the facts of the nepotism case are proven, the governor’s action would amount to a knowing and willful violation of the ethics code.

The governor’s lawyers would not discuss the case, and his press secretary, Amy Kempe, said she did not expect him to discuss the situation.

The action yesterday followed the commission’s refusal in June to issue a legal opinion retroactively approving one of Carcieri’s first hires, Stephanie Accaputo, the daughter of his wife’s brother and a worker in Carcieri’s 2002 campaign for governor.

The governor has already settled three ethics cases with the commission, thereby avoiding prosecution on the charges. They include:

• An accusation that the governor violated the ethics code when he accepted tickets from Fleet Bank to watch a New England Patriots football game from the bank’s luxury box at Gillette Stadium in December 2003.

• The governor’s failure to file a mandatory financial disclosure statement on time in 2004.

The governor settled both the football tickets and disclosure filing cases together by agreeing to pay a $750 fine in 2005.

• A third accusation that Carcieri solicited campaign contributions from state employees during his reelection campaign in 2006. The governor settled that case last year by agreeing to pay a $1,000 fine.

Accaputo was hired in late 2002 to work in the governor’s constituent-affairs office at a salary of $37,781 per year. She is now an administrative support specialist, with a salary of $52,119, according to the governor’s office.

The ethics code has since 1991 prohibited officials from using their office to benefit relatives, “whether by blood, marriage or adoption,” and it listed nieces among the relatives covered. Carcieri’s legal counsel, Kernan F. King, argued at a commission meeting June 17 that the ethics code didn’t clearly forbid hiring nieces-in-law.

That prompted Cheit to ask, “What part of ‘by marriage’ don’t you understand?”

Cheit said at the same meeting that it wasn’t appropriate for the governor to ask now for a ruling “going back to bail him out on this.” The commission normally issues advisory opinions to officials who ask about the propriety of actions they expect to take, but not approving actions already taken.

The commission staff said that while the prohibition was in the code at the time, understanding it could have required reading three sections of the code.

But the possibility that the governor or his staff had trouble understanding the anti-nepotism provisions in 2002 only prompted questions about why Carcieri didn’t ask for a legal opinion then about hiring his relative.

Since the June meeting, lawyers Christopher S. Gontarz and Thomas M. Dickinson have replaced King. They filed a motion Monday afternoon asking that Cheit drop out of the Carcieri case because of his remarks at that meeting.

William J. Conley Jr., the commission’s legal counsel, said yesterday that if Cheit dropped out because he opposed granting the governor a favorable advisory opinion, it would set “a dangerous precedent” for the commission.

By the same reasoning, Conley said, any commission member who opposed issuing a favorable advisory opinion shouldn’t vote on the same case later if a complaint was filed against the official involved.

By that logic, he said, the entire commission could easily be disqualified. That would put the Ethics Commission out of business.

Cheit declined to drop out of the case.

Under the commission’s normal procedure, once the staff investigation is complete, the commission will decide whether there is probable cause to think the governor broke the ethics code. If it finds that there is, the governor would be prosecuted in a trial-like hearing before the commission unless he settles the case.

Like the governor in his previous ethics cases, most officials settle their cases, sometimes paying thousands of dollars in fines.

blandis@projo.com