HARTFORD — Officials from the Connecticut Democratic Party said Thursday they've learned federal officials have ended a criminal investigation into fundraising for Gov. Dannel P. Malloy's 2014 re-election campaign.

The party's attorney, David Golub, said he received a phone call late Wednesday from the U.S. Attorney's Office, notifying him the nearly year-long probe, which involved a grand jury, has concluded. Golub declined to elaborate on the conversation, but said "there's nothing hanging" when asked if there are other possible avenues for the federal investigation.

A spokesman for the U.S. Attorney's Office in Connecticut declined to comment.

Mark Mandell, the party's executive director, said Democrats can be sure now this issue is behind them.

"We have always been confident that there was no wrongdoing in the way in which the Connecticut Democratic State Central Committee operated during the 2014 elections and that we complied fully with both the letter and spirit of state and federal campaign finance laws," Mandell said in a written statement.

Appearing at an unrelated event in Waterbury, Malloy said he didn't want to discuss the matter at length.

"The party fully cooperated, turned over thousands of documents, turned over documents that had not been previously provided by others, and apparently the U.S. Attorney's Office reached the appropriate conclusion," said Malloy, who also is a former prosecutor.

Malloy signed an affidavit in 2014 agreeing he would not supplement the $6.5 million in public funds he received from Connecticut's public campaign financing system, the Citizens Election Fund, for his campaign. Campaign staff also signed documents agreeing to abide by the program's rules.

Malloy went on to win his re-election bid.

Federal investigators later began looking into whether the party illegally spent $278,000 in political contributions to pay for a mailing benefiting Malloy's campaign. The money came from government contractors and was earmarked for federal candidates. But the state Democratic Party argued the mailers touting Malloy's record were part of an overall "get-out-the-vote" effort that also helped federal candidates because the mailers included a phone number to get rides to the polls and polling hours.

The matter first came under scrutiny by the state during the campaign.

Last June, the Democratic State Central Committee and Malloy's campaign committee reached an agreement with the State Elections Enforcement Commission, consenting to make a $325,000 payment to the state to end the dispute over whether the funds were illegally spent. They also agreed to use funds that comply with state law for any future campaign activity.

Michael Brandi, the commission's executive director, said at the time that the agreement eliminated a loophole that allowed federal funds, including those contributed by state contractors and lobbyists, to be spent on state elections.