NEW ORLEANS - For months, BP has complained that a Louisiana attorney who is administering its settlement with tens of thousands of Gulf Coast businesses and residents has made decisions that expose the company to what could be billions of dollars in fictitious claims arising from the 2010 oil spill in the Gulf of Mexico.

Now the court-appointed administrator himself is investigating allegations that could provide the London-based oil giant with fodder for its argument that it hasn't gotten a fair shake from the claims-processing team.

Lafayette-based lawyer Patrick Juneau confirmed Friday that he has opened an internal probe of alleged misconduct by one of his staff attorneys, Lionel H. Sutton III.

Sutton resigned Friday morning, Juneau spokesman Nick Gagliano told The Associated Press.

A report outlining the allegations, a copy of which was obtained by the AP, accuses Sutton of "writing polices" that benefited himself and other plaintiffs' lawyers. It does not elaborate.

Prepared by Juneau's office, the report also says a "confidential source" who contacted Juneau's security chief accused Sutton of trying to influence a claim filed by New Orleans-based Andry Law Firm. The same firm allegedly paid Sutton a portion of settlement proceeds for claims he had referred to it before he went to work for Juneau.

Juneau provided the report to U.S. District Judge Carl Barbier during a meeting in his chambers Thursday. The administrator has pledged to thoroughly investigate the claims involving Sutton, who started working for his office in November 2012, according to the report.

Both BP and claimants "rightfully expect fairness and objectivity from this claims process," Juneau wrote.

"Our goal is to operate in an efficient, transparent and fair manner. All allegations are taken seriously and investigated thoroughly."

But in its own statement Friday, BP said only a "comprehensive and independent investigation will ensure the integrity of the claims process."

Sutton acknowledged in an email late Thursday that he had been told he was suspended "pending an investigation of an anonymous allegation against me."

"I have not been made aware of the substance of the allegation or the status of the investigation," Sutton wrote. "Once this is resolved, I would be happy to discuss it all with you."

According to the report, Sutton denied the allegations when Juneau discussed them with him.

"Sutton advised Juneau that he did not retain any interest in the claims or clients and the allegations were 100 percent incorrect," the report says.

But the report also cites passages from a string of email exchanges in which Sutton allegedly asks about his cut of nearly $500,000 in settlement payments to an individual who had filed several seafood-related claims.

In response to a lawyer who emailed him in January 2013 and asked him about his fee, Sutton allegedly responded, "They sent you the check for my fee. The total fee on (the claimant) was 10k (+ or -). They sent you 5 for me and kept the other 5."

Jonathan Andry, a lawyer at the firm that allegedly paid Sutton, didn't immediately respond to messages left at his office and with his answering service.

The report indicates that Juneau's security head, David Welker, notified the FBI's New Orleans division about the lawyer's alleged misconduct. Welker until recently was the special agent in charge of the FBI office in New Orleans.

An FBI spokeswoman in New Orleans declined to comment Thursday.

Before the allegations even surfaced, BP PLC had sued to block what could be billions of dollars in settlement payouts to businesses over the spill. The company has accused Juneau of trying to rewrite the terms of the deal and asserts that he has made decisions that expose the company to fictitious losses that were never contemplated in the settlement.

Judge Barbier, who is overseeing the massive settlement, appointed Juneau last year and has upheld his decisions for calculating payments. BP has appealed, and the 5th U.S. Circuit Court of Appeals is scheduled to hear the case in July.

It's unclear how much influence Sutton had over the process of evaluating and paying scores of claims spawned by the deadly Deepwater Horizon disaster, which killed 11 rig workers and led to the nation's offshore oil spill.

The report prepared by Juneau's office Thursday doesn't elaborate on the allegation from the confidential source that Sutton was "writing policies within the (settlement program) that ultimately may benefit his friends who are attorneys and himself."

The spill began in April 2010 after the BP-leased drilling rig Deepwater Horizon exploded off the Louisiana coast, killing 11 workers. Roughly 200 million gallons of crude oil were released from the Macondo well a mile under the Gulf surface. Marshes, fisheries and beaches from Louisiana to Florida were fouled by the oil until a cap was placed over the blown-out well in July 2010.

BP set up a compensation fund for individuals and businesses affected by the spill and committed $20 billion. The claims fund initially was handled by lawyer Kenneth Feinberg but Juneau took over the processing of claims after the settlement was reached last year.

Juneau's office announced in May that it has determined more than $3 billion in claims are eligible for payment through the settlement agreement. More than 162,000 claims were filed and more than $2 billion had been paid to claimants as of May 6.