WASHINGTON — The Justice Department inspector general announced Thursday that he will review broad allegations of misconduct involving FBI Director James Comey and how Comey handled the probe of Hillary Clinton’s e-mail practices.

The investigation will be wide-ranging, encompassing Comey’s various letters and public statements on the matter and whether FBI or other Justice Department employees leaked nonpublic information, according to Inspector General Michael Horowitz.

The inspector general’s announcement drew praise from those on both sides of the political aisle and again put a spotlight on Comey, who emerged as a controversial figure during the 2016 race. Democrats, including Clinton, have blamed the FBI director for the Democratic candidate’s loss, arguing that the renewed e-mail inquiry and Comey’s public missives on the eve of the election blunted her momentum.

Comey has also been criticized for months by former Justice Department officials for violating the department’s policy of avoiding any action that could affect a candidate close to an election. President-elect Donald Trump has notably declined to commit to keeping the FBI director.

Brian Fallon, a former Clinton campaign spokesman, praised the investigation Thursday. ‘‘This is highly encouraging and to be expected given Director Comey’s drastic deviation from Justice Department protocol,’’ Fallon said. ‘‘A probe of this sort . . . is utterly necessary in order to take the first step to restore the FBI’s reputation as a nonpartisan institution.’’

Lawmakers and others had called previously for the inspector general to investigate the FBI’s actions regarding the Clinton probe ahead of the election, alleging that Comey violated longstanding policies with his communications about the case and that information seemed to have leaked inappropriately — perhaps to former New York City mayor Rudolph Giuliani, a Trump supporter.

Horowitz said Thursday that he will explore the circumstances surrounding the actions of Comey and others, though he will not relitigate whether anyone should have faced charges.

‘‘The review will not substitute the OIG’s judgment for the judgments made by the FBI or the Department regarding the substantive merits of investigative or prosecutive decisions,’’ Horowitz said in his statement, using an abbreviation for the office of the inspector general.

Comey said in a statement: ‘‘I am grateful to the Department of Justice’s IG for taking on this review. He is professional and independent and the FBI will cooperate fully with him and his office.’’

The FBI’s probe into whether Clinton mishandled classified information by using a private e-mail server when she was secretary of state has long been controversial.

Perhaps most notably, Comey on Oct. 28 — after previously announcing publicly that he was recommending no charges in the case — sent a letter to congressional leaders telling them that agents had resumed the Clinton probe after finding potentially relevant information in an unrelated case. That investigation involved disgraced former congressman Anthony Weiner, the estranged husband of top Clinton aide Huma Abedin.

The day before, senior Justice Department leaders had warned Comey not to send the letter, because it violated two longstanding department policies: discussing an ongoing investigation, and taking any overt action affecting a candidate so close to an election.

Comey has notably declined to talk about any possible investigations of Trump or his campaign, as recently as this week rebuffing requests from legislators to confirm that agents were looking into any such matters.

Comey sent a second letter to Congress on the Clinton case, just days before the election, declaring that the investigation was complete and that he was not changing the decision he had made in July to recommend no charges. But the damage — in the minds of Clinton supporters, at least — had been done.

Horowitz wrote that he will explore ‘‘allegations that Department or FBI policies or procedures were not followed’’ in connection with both letters. When he is finished, his office will probably issue a lengthy report detailing what it has found, as it has done in other high-profile matters, though it is also possible he could recommend criminal charges for anyone found to have broken the law. The probe could take a significant amount of time.

Horowitz wrote that his inquiry will extend back to at least July, when Comey announced he was recommending the Clinton case be closed without charges. He wrote that he will explore ‘‘allegations that Department and FBI employees improperly disclosed non-public information’’ — potentially a reference to Giuliani, who seemed to claim at one point he had insider FBI knowledge. Horowitz also said he would explore whether FBI Deputy Director Andrew McCabe should have been recused from the case. McCabe’s wife, Jill McCabe, ran for a Virginia Senate seat and took money from the political action committee of Virginia Governor Terry McAuliffe, a fierce Clinton ally.

Horowitz wrote that he would delve more deeply into the FBI publishing, just days before the election, 129 pages of internal documents from a years-old probe into former president Bill Clinton’s pardon of fugitive Democratic donor Marc Rich. And he said he would also probe whether Peter Kadzik, the Justice Department’s assistant attorney general for legislative affairs, ‘‘improperly disclosed non-public information to the Clinton campaign and/or should have been recused from participating in certain matters.’’

Notably absent from the list is Attorney General Loretta Lynch’s controversial meeting in June with former president Clinton aboard her plane on the tarmac of the Phoenix airport. The conversation created the appearance to some that the attorney general was politically compromised.