After a yearlong investigation into the finances of U.S. Rep David Rivera, officials will not be charging the Republican with a Florida state crime.

In a 16-page memo released on Wednesday by Miami-Dade County State Attorney Katherine Fernandez Rundle, law enforcement officials concluded that they "have exhausted all active criminal investigative avenues" and have closed the case despite lingering questions.

The investigation initially began last July when the Florida Department of Law Enforcement identified "potential ethical violations" by Rivera, including that as a state representative he sought to hide a $1 million contract with a Florida gambling company. Released Wednesday to the Associated Press, the report also said he used campaign funds to pay for Florida House of Representatives activities already reimbursed by the state.

Although state prosecutors found no criminal violations, Rivera still faces a federal probe. The freshman congressman's maiden campaign drew national attention because his heavily Latino district in South Florida was considered one of the few in the nation up for grabs between the two major parties in 2010.

Alicia Valle, a spokeswoman for the U.S. Attorney's Office in Miami, declined to comment on the federal case Wednesday.

Rivera, a Republican, called the investigation a fishing expedition that became a wild goose chase.

"As he has always maintained, Congressman Rivera has at all times acted in compliance with both the letter and spirit of Florida and federal campaign finance laws and has timely and properly reported all personal income," Rivera's campaign said in a statement emailed to the AP.

"Any funds raised and spent in relation to Congressman Rivera's campaigns for the State House, Republican State Executive Committee, or U.S. Congress, were done with the strictest adherence to all applicable legal standards.," the statement continued. "Any suggestion to the contrary is completely false."

Following the July report, Rivera’s camp issued a statement, "FDLE was provided with specific and detailed information refuting all of their false and unfounded allegations against Congressman Rivera."

Allegations involving Rivera's campaign finances first surfaced at the close of the 2010 congressional campaign, but they mostly related to earlier state campaigns.

The department's report states that even though Rivera did vote on multiple pieces of legislation directly affecting the company with whom he had a contract, his activities did not violate Florida's unlawful compensation law.

"However, the investigation did identify potential ethical violations based upon Mr. Rivera's behavior and intent," the report said, including taking steps to disguise his relationship with a special interest group.

The report also found more than $65,000 in credit card charges that appeared to be for personal expenses but that were paid for with campaign funds. Those included "pet services, dry cleaning, dental care, medical services, entertainment and travel expenses for his girlfriend," the report said.

The separate memo released Wednesday by prosecutors cited other questionable transactions and expenses, including Rivera's explanation that he needed girlfriend at his side at campaign events.

"As a single man running as a political conservative, it was necessary for him to appear at campaign related events with a female escort," the memo quoted Rivera as saying, continuing that he maintained "it was appropriate and permissible to pay for his female companion's expenses as well, as they were essential to his election campaigns."

The FDLE closed its investigation on April 4. The prosecutors' memo released Wednesday concluded in some cases that charges could not be brought because the two-year statute of limitations had expired.

In a second email sent Wednesday night to the AP, the Rivera campaign criticized the memo and said Rivera was pleased the state probe is over.

"While the State Attorney's report is an outrageous and libelous distortion of facts filled with lies, fabrications, and innuendo, Congressman Rivera is pleased the State Attorney has concluded their frivolous investigation and has not found any wrongful conduct on his part. Congressman Rivera provided the State Attorney with detailed evidence refuting all of their false allegations, none of which they included in their report," the statement said. "It is unfortunate that the State Attorney has chosen to try and justify their waste of taxpayer dollars by hiding behind false and politically motivated accusations which they simply cannot prove. In the end, however, one fact remains, Congressman Rivera has been exonerated."

Florida Democrats on Wednesday were quick to point out that Rivera is under federal investigation.

"He's still failing to raise money," Florida Democratic Party Spokesman David Bergstein said in a statement. "He still doesn't have the support of the GOP. He's still on the wrong side of the issues that matter to Florida's middle class, and we're still going to win FL-26."

Still, Democrats have had a tough time recruiting candidates to run against Rivera this year. A former fire chief-turned-state lawmaker dropped out of the race after the party criticized his fundraising efforts. The current Democratic candidate lives outside the district and has never run for public office before.

Based on reporting by the Associated Press.

Follow us on twitter.com/foxnewslatino
Like us at facebook.com/foxnewslatino