D.C. Council member Harry Thomas Jr. intentionally diverted more than $300,000 in public funds intended for youth baseball programs and spent it on a luxury sport-utility vehicle and personal travel, Attorney General Irvin B. Nathan said Monday.

In a lawsuit filed in D.C. Superior Court, Nathan alleged that Thomas (D-Ward 5) used the funds for his Team Thomas organizations to purchase a $59,000 Audi SUV and pay for jaunts to Las Vegas and Pebble Beach, Calif. Nathan seeks to force Thomas to repay the city money that he is accused of rerouting to his operation, plus damages and other costs totaling more than $1 million. Thomas denied any wrongdoing.

The allegations represent the latest in a series of scandals that have tarnished the District’s top elected officials and given the appearance of a government in disarray. Nathan announced his findings just hours before former mayoral candidate Sulaimon Brown (D) testified under oath at a council hearing that Mayor Vincent C. Gray (D) gave him improper payoffs and a job in a quid pro quo to smear his key opponent.

Several council members also are caught up in political controversies, including neglecting to account for campaign donations, failing to pay taxes and purchasing luxury vehicles with taxpayer funds. The scandals are weighing on a city trying to rebound from an economic slump and last year’s divisive mayoral campaign.

“We are extremely disappointed in this violation of public service by Mr. Thomas,” Nathan said, calling his behavior “willful, intentional and knowing. ”

Nathan has asked U.S. Attorney Ronald C. Machen to consider filing criminal charges against Thomas. William Miller, Machen’s spokesman, said federal prosecutors have been investigating Thomas.

“The U.S. Attorney’s Office is aware of the referral and will review the information . . . as we continue our investigation,” Miller said in a statement.

Thomas, the son of a respected three-term council member who died in 1999, vowed to fight the allegations. “There is no settlement that I would make that would imply that there was some wrongdoing on my part,” he told reporters in front of the John A. Wilson Building.

Thomas, who arrived at his news conference in the blue Audi, said he would provide proof that the money was spent on sport programs and maintained that his business paid for the vehicle. He added that he would not resign his council seat or step down from his chairmanship of the powerful Economic Development Committee.

Timothy Day, a Republican who first raised the accusations against Thomas during an unsuccessful campaign to unseat him last fall, called his alleged actions “a disgrace” and added that “his lifelong quotes of giving back to the children were false. He clearly gave more to himself.”

D.C. Council Chairman Kwame R. Brown (D) said in a statement that he was “greatly disheartened” by the allegations. Brown met with Thomas on Monday and said he would issue “a plan of action” Tuesday.

Nathan’s allegations again bring unwanted attention to a council marred for months in embarrassing political controversies.

Gray is accused of giving jobs to unqualified campaign supporters. Brown has been rebuked for purchasing a luxury SUV upon assuming office in January and for his failure to report a quarter-million dollars in donations during his 2008 campaign for a council seat. Council member Michael A. Brown (D-At Large) failed to pay city property taxes, and member Marion Barry (D-Ward 8) was censured and stripped of his committee chairmanship last year for giving a city contract to a former girlfriend.

Thomas’s supporters said they would wait until the lawsuit is fully heard before judging the council member.

“From a community perspective, it’s pretty regretful these allegations have been made,” said Angel Sherri Alston, an advisory neighborhood commissioner who is president of the Ward 5 Democrats. “These are very serious allegations, but there is still a presumption of innocence until proven guilty. Until then, we will keep council member Thomas in our prayers.”

The allegations concern two district groups controlled by Thomas: a for-profit business created in 2004, which remains active, and a now-defunct nonprofit group created shortly after Thomas joined the council.

The nonprofit group never obtained federal tax exempt status, the lawsuit alleges, and it was never licensed to accept charitable contributions. Yet it collected some money, largely through a pair of fundraisers held at Langston Golf Course, and Nathan alleges they paid for travel and a Washington Nationals suite worth $696, not the youth sports programs Thomas advertised to donors.

In his report, Nathan also lays out a scheme in which Thomas is alleged to have used his influence to send taxpayer money to his Team Thomas groups.

In 2007, the council voted to budget $400,000 for “youth baseball programs” via the Children and Youth Investment Trust Corp., a public-private intermediary that offers grants to nonprofits serving youths. Although the council did not identify a specific organization to receive the money, Thomas, it is alleged, directed the trust to give it to the Langston Golf Course.

A grant of $392,000 was sent to the course’s foundation, Langston 21, whose board of directors included the longtime resident golf pro and Thomas friend James Garvin. Nathan’s lawsuit alleges that Garvin helped reroute three-quarters of those funds back to the Team Thomas organizations.

Nathan said Monday that Thomas’s council staff fabricated documents for the Langston 21 foundation, describing programs and sports camps that never existed and never mentioning Team Thomas. Yet the council member personally picked up checks from Garvin and Langston 21 President Marshall Banks made out to Team Thomas, Nathan said.

On Feb. 8, two days after picking up two checks worth $75,000, Thomas took a cashier’s check to Tischer Audi in Silver Spring, where he used it to buy a 2008 Audi Q7 4.2 Quattro Premium SUV, Nathan alleges.

The cashier’s check and a $9,000 trade-in for his Dodge Durango weren’t quite enough to complete the purchase. To pay the $1,074 difference, Thomas used the Team Thomas charity’s debit card.

According to Nathan, the vehicle was initially titled under HLT Development, but Thomas had the car retitled in his own name in May 2009. To justify the nearly $60,000 apparently spent on the Audi, a report provided to the Children and Youth Investment Trust included an invoice for $58,472 worth of training equipment. Langston 21, according to the lawsuit, saw none of that equipment.

Last fall, Thomas called the initial allegations against him a “useless fishing expedition,” and he sought to portray himself as a victim of a political vendetta by then-Mayor Adrian M. Fenty (D) and Peter Nickles, Fenty’s attorney general. Frederick D. Cooke, Thomas’s attorney, called Nickles’s probe “blatant retribution” in one court hearing.

Nathan, appointed by Gray, assumed the investigation in January after Nickles left office. Observers questioned whether Thomas, as a Gray ally, would be subject to as tough a probe under Nathan.

Nathan said the Langston 21 foundation has agreed to pay the city $86,000 for the portion of the earmarked funds that it did not pass on to the Team Thomas groups. Vandy L. Jamison Jr., an attorney for Banks and Garvin, declined to comment.

Staff writer Del Quentin Wilber contributed to this report.