ISTANBUL >> The indictment of a prominent Turkish businessman unsealed last week has made an unlikely hero of a man most Turks had never heard of: Preet Bharara, the U.S. attorney for the Southern District of New York, who brought the charges against the tycoon, Reza Zarrab.

In recent days, as news of Zarrab’s arrest circulated here, Bharara became a social media sensation among Turks who have increasingly lost confidence in the independence of their country’s institutions, particularly the judiciary, after a Tuesday morning post on Twitter: “Reza Zarrab to soon face American justice in a Manhattan courtroom.”

Since that message was posted, the number of Bharara’s Twitter followers has soared to 245,000 from a few thousand. An anonymous poem written in Turkish about Bharara, which notes his reputation as a fearless prosecutor of Wall Street malfeasance, gained traction online and begins, “There is a prosecutor in America, he is unshakably loyal to the law, now it is the turn of Reza, what a great man you are, Preet Bharara.”

Countless Turks have sent Bharara messages on Twitter, congratulating his efforts, and he responded to one post in which the writer offered any number of gifts from Turkey: raki, a Turkish liquor; a carpet; kebab; or Turkish delight.

Bharara wrote back, “Well, I do love shish kebab but I don’t think I can accept gifts just for doing my job.”

Zarrab, a flamboyant gold trader who is married to a Turkish pop star, was once a constant in the gossip pages of this city’s newspapers. He became a household name in Turkey in late 2013 when a corruption inquiry became public with dawn police raids against Zarrab, several other businessmen and the sons of three Cabinet ministers.

The investigation — focused on those in the inner circle of Recep Tayyip Erdogan, then the prime minister and now president — became a national sensation, and it was seized upon by the many critics of Erdogan and his Islamist Justice and Development Party as evidence of abuse of power.

But Zarrab quickly disappeared from view, along with the splashy headlines, as the investigation was quashed through a series of purges of the police and judiciary.

Now, though, Zarrab, 33, a dual citizen of Turkey and Iran, is back in the news, having been arrested in Miami on Saturday on charges of helping Iran evade sanctions imposed over its nuclear program.

As Zarrab sits in jail in the United States, having been denied bail, his case has again captured the imagination of many Turks who believe the original corruption inquiry was swept under the rug and who now hope that an American court will achieve what Turkish courts were unable to: a full and fair hearing of corruption allegations that touched the highest levels of government here.

The 2013 inquiry mainly focused on corruption in the construction business and the public financing of real estate development. It also cast a spotlight on an issue that had long been a concern of the United States: the role of Turkey in helping Iran evade international sanctions over its nuclear program. One of the targets was the chief executive of the state-owned Halkbank, which the United States had long accused of working with Iran to evade sanctions in a scheme that involved using gold to buy Iranian oil and gas.

Zarrab was accused of aiding that scheme, but he was exonerated in Turkey after his arrest in 2013. The U.S. indictment, though, does not mention Halkbank. It lists numerous counts of money laundering and bank fraud, and it accuses Zarrab and others of conspiring for years “to violate and evade United States sanctions against Iran and Iranian entities,” Bharara said in a statement released this week with the indictment.

Zarrab’s arrest gave many Turks something to smile about last week, as they are otherwise unnerved by a series of terrorist attacks, including a suicide bombing last weekend on Istiklal Avenue, Istanbul’s long pedestrian shopping street in the heart of the city’s European quarter.

It is unclear whether the U.S. investigation intersects at all with the allegations Zarrab faced in Turkey. But critics of the Turkish government, who say the corruption inquiry was silenced through firings of the police and prosecutors who carried it out, are hoping that Zarrab, in trying to save himself, sings, and sings loudly.

Two articles, side by side, in Thursday’s Hurriyet Daily News, a Turkish newspaper, highlighted the divergence of Turkish and American justice. One reported that an arrest warrant had been issued for a Turkish prosecutor involved in the original graft case; the other was about Zarrab’s having been denied bail in the United States.

Semih Idiz, a columnist for the newspaper, wrote on Thursday about the “celebratory mood in antigovernment circles in Turkey” over the arrest. He added that “many are waiting avidly to see what he says in court, since Turkey was the base of his alleged illegal operations.”

At the time the corruption inquiry became public in 2013, Erdogan and others blamed allies of Fethullah Gulen, a popular Muslim cleric who lives in exile in Pennsylvania, for the investigation.

Gulen had built up a network of followers in the police and judiciary over decades and was once an important ally of Erdogan’s. But the two had a falling out, and the disagreements crystallized over the corruption investigation.

The response from Erdogan was swift: First came the purging from government of those thought to be followers of Gulen — on suspicion that they were plotting a coup — followed by the seizure under terrorism laws of many businesses and news outlets said to be linked to Gulen.