David Rivera spent more money saying `thank you' to voters than any other Florida lawmaker. Now investigators are examining some of those expenses.

After dropping out of a state Senate race last year to run for Congress, David Rivera set aside tens of thousands of dollars from his dormant Senate campaign account to say ``thank you'' to supporters of a race he never intended to finish.

Rivera paid the money to a company called ACH Fundraising Strategies -- a Miami-based business founded by the daughter of a longtime aide. He cut a $50,000 check to ACH on July 15, 2010 -- the day before the firm was incorporated as a business.

Those "thank you campaign'' dollars to ACH are now being scrutinized as part of an expanding criminal investigation of the Republican congressman's personal and campaign accounts by Miami-Dade police and prosecutors, The Miami Herald has learned.

Rivera, who was elected to Congress in November after eight years in the Florida Legislature, declined to be interviewed for this article. In a statement issued through his campaign office, Rivera said all his expenses were proper, though he neither provided details of what ACH did for the money, nor any records verifying the expenses.

It has always been campaign policy not to disclose details related to campaign strategies and tactics, past, present or future,'' the statement said. "The campaign reports speak for themselves. All information provided was accurate and all expenses properly reported.''

State law allows candidates to spend excess campaign funds on "thank you'' advertising, and lawmakers commonly take advantage of this to pay for mailers or other ads targeted at reliable voters in their districts, to maintain goodwill and name recognition.

But no one in Florida says thank you like David Rivera.

From 2004 to 2010, Rivera spent almost $243,000 in campaign donations on "thank you'' expenses -- far more than any other state candidate, and accounting for almost one-quarter of all the thank-you money spent in Florida during that period, a Miami Herald analysis of state campaign data found.

UNSPENT DONATIONS

More than $122,000 of Rivera's thank-you expenses went to consulting firms, including two payments to ACH totaling $75,000, records show.

Rivera "has always felt a strong desire to express this appreciation after every election and will continue to do so,'' his campaign statement said.

The $75,000 paid to ACH last year came from Rivera's state Senate campaign -- a campaign Rivera abandoned when he decided to run for Congress on Feb. 25, 2010. Rivera's Senate account held about $379,000 in unspent donations when he launched his congressional run, but campaign-finance laws prohibited him from transferring that money to the federal race.

Rivera, who served as the treasurer of his Senate campaign, made his first $50,000 payment to ACH about five months later, on July 15 -- one day before ACH was incorporated, records show. The company received $25,000 more on Aug. 30.

ACH was founded by Alyn Cruz Higgins, 31, a Miami political fundraiser and consultant. Her mother, Alina Garcia, is an aide on Rivera's congressional staff, after working for Rivera for years in the state Legislature.

FIRM IS DISSOLVED

Higgins' attorney, Robert Fernandez, said her company provided "consulting services'' for Rivera's thank-you campaign. In a statement, he said Higgins "had been highly recommended by various people to David Rivera's State Senate campaign.''

Fernandez also said Higgins filed paperwork to dissolve ACH on Dec. 23.

Higgins listed her mother's home as the address of ACH in corporate records filed with the state. However, Rivera's campaign reports showed a different address for ACH: the home of Higgins' sister, Alany Cruz.

Cruz told The Miami Herald she was unaware of the payments, and she could not explain why the campaign records list her home as the firm's address.

"I'm a little confused myself,'' said Cruz, a schoolteacher. ``I don't know about that.''

Cruz donated $500 to Rivera's Senate campaign in 2009, but Rivera returned the donation, along with dozens of others, after launching his congressional bid.

Higgins is a former mental-health counselor who worked in the office of Miami political consultant Steve Marin until August. Her company also received $12,000 in consulting fees this fall working on the campaign of U.S. Sen. Marco Rubio, a close ally and friend of Rivera's.

Higgins also assisted Rivera's 2006 state House campaign. She received a $3,500 payment from that campaign as reimbursement for postage, records show.

Rivera declined to provide The Herald with any contract with ACH, and his campaign said any invoices submitted by the company were "inaccessible or in storage.''

Fernandez also declined to provide the newspaper with its invoices, saying they were ``confidential.''

"Any negative inference in your article about the services provided by ACH Strategies would be based purely on misinformation and/or speculation considering that ACH Strategies has not released its business records,'' Fernandez said in his statement.

In 2006, Rivera also spent $15,000 on a "thank you'' campaign through a company called Millennium Marketing -- a company co-owned by Rivera's 70-year-old mother and his godmother.

$15K IN CONSULTING

Rivera also paid Millennium an additional $15,000 for "campaign consulting'' on Sept. 27, 2006 -- two days after Millennium was incorporated, records show.

In October, a Rivera spokeswoman told The Herald that Millennium "was paid to organize and coordinate the thank-you campaign, which included overseeing media, mail, telecommunications and community outreach.''

Last week, Rivera provided The Herald with copies of mailers he said were produced by Millennium.

"Thank you for your civic virtue, your patriotism and your support,'' said one mailer featuring photos of a young Rivera with Ronald Reagan and George W. Bush.

Rivera's ties with Millennium are at the heart of the criminal investigation. Millennium received more than $500,000 in secret payments from the Flagler Dog Track as part of an agreement with Rivera to manage a political campaign on behalf of parimutuels seeking voter approval for slot machines in Miami-Dade County.

Rivera long maintained that he received no income from his work for the track. But earlier this month, he acknowledged receiving $132,000 from Millennium -- payments Rivera had not previously disclosed in financial disclosure forms.

Rivera said the payments were loans from his mother's company, which he repaid after he won election to Congress on Nov. 2. Rivera has said he did not believe he was obliged to report the loans under state and federal disclosure rules.