A construction company whose office FBI agents raided last year as part of a federal investigation into Mayor Eric Adams’ 2021 campaign illegally erected several stories of an East Village residential project without obtaining a key permit, Gothamist has found.

KSK Construction completed at least five stories at 280 East Houston St. near the end of February, according to photos taken of the site by the news blog EV Grieve. At the time, the firm had not obtained the necessary approvals to begin above-ground work on its 12-story project, according to the city’s Department of Buildings.

There is no known connection between the construction work in February and the federal probe but the oversight comes amid intense scrutiny around the Brooklyn-based builder. Penalties for such violations are relatively small, but an East Village resident said he found the builder’s ties to the mayor suspicious.

“I think this whole thing stinks,” said Tice Brown, who lives across the street from 280 East Houston St., referring to the project.

The buildings department had not noticed the missing building permit until Gothamist inquired about the project last month. The department confirmed that the work was done illegally, and that the company did not receive the required permit until February 29 — after five stories of the building were already up. The 157-unit building topped out in May.

A KSK representative declined to comment on the project and hung up on a Gothamist reporter.

KSK, which is widely reported to be owned by Turkish immigrants, constructs luxury condos and hotels across the city. It gained notoriety last November after a raid on Adams’ chief fundraiser exposed a federal corruption investigation. According to multiple reports, the search warrant indicated that federal agents are looking into KSK’s relationship to the campaign, as well as illegal donations from Turkish officials.

KSK’s Williamsburg office was among those searched by the FBI, according to CNN.

Campaign finance records show 11 KSK employees donating nearly $14,000 to the Adams campaign. Under the city’s public matching funds program, which is intended to reward candidates raising money from small donors, Adams was eligible to earn an additional $18,000 in taxpayer-funded money from those donations.

Neither KSK employees nor Adams have been charged with wrongdoing.

Brown, the project’s neighbor, said he discovered the contractor had not filed all the necessary permits after investigating a separate issue. In May, he filed a lawsuit against the city’s buildings department and the developer of the project, a group of LLCs, for failing to follow city zoning regulations that require a 30-foot rear yard setback.

In an interview with Gothamist, Brown accused the Department of Buildings of having a “relaxed policy for zoning and permitting rules for projects whose general contractors nurse a warm relationship with the city’s political elites.” He said the violation over the missing permit raises concerns about the building’s safety.

“Rules must exist for all or for none,” he added.

Andrew Rudansky, a buildings department spokesperson, said the city’s failure to notice the missing permit was an oversight. KSK had one required permit in place but was missing an additional approval. He said there was no reason to suspect that the building was not safe.

“DOB was not previously informed about this issue at the time, but as soon as we were, we began a review of agency records,” Rudansky said in a statement.

But online building records show a 311 complaint filed on Jan. 27 that specifically claimed work was being done without a building permit. City officials dismissed the complaint as unsubstantiated because the project did have some — though not all — of the required permits.

A spokesperson for the mayor’s campaign declined to comment and referred questions to City Hall.

Fabien Levy, deputy mayor for communications, said the fact that the DOB issued a violation was proof the city held the builder accountable.

As a result of the violation, a hearing before the city’s Office of Administrative Trials and Hearings has been scheduled for Aug. 29. The maximum penalty is $6,250.

The firm could face a more severe penalty stemming from Brown’s lawsuit. As part of that process, he and KSK are set to appear before the city’s Board of Standards and Appeals, a five-member commission that rules on zoning issues.

Mikhail Sheynker, Brown’s lawyer, said he is asking the city to issue a stop work order on the project until the building can come up with a plan to remedy the violation.

David Brand contributed reporting.