Multiple sources have confirmed to Mission Local that, at around mid-day Wednesday, FBI officials dropped in on San Francisco’s Department of Building Inspection.

The feds allegedly entered the Planning Department, which is next door to the Department of Building Inspection headquarters on the 1600 block of Mission, and then migrated to an area where DBI stores servers.

Mission Local is told that the federal officials were searching for files related to 555 Fulton St. That project is owned by Z&L Properties. Its billionaire co-owner, Zhang Li, purportedly lavished “some stone,” expensive liquor and seven-star accomodations on San Francisco Public Works boss Mohammed Nuru during a Chinese trip, according to the FBI. In exchange, Nuru purportedly pulled strings to help along the project.

Nuru was last week arrested and charged with fraud related to this and other allegations of public corruption revealed in a long-running FBI probe. He was initially arrested on Jan. 21, but released after promising to cooperate with the probe and keep its existence secret. He allegedly did the opposite, however, and is charged with lying to the FBI about it. He faces up to 25 years in prison.

Within the 75-page complaint against Nuru and restaurateur Nick Bovis unsealed last week, the disgraced Public Works head is caught on a federal wiretap purportedly going over a litany of issues he’d like to see remedied on the 555 Fulton project.

Searching on city databases, it seems that there are no records for some of the work at 555 Fulton being described by Nuru in the federal wiretap — and, importantly, that other work appears to have approved “over the counter,” when far more extensive time and scrutiny should have been been applied.

It is unclear if the feds today were able to locate the files they were purportedly seeking on DBI’s servers.

Permitting on the 555 Fulton project was handled by deeply connected expediter Walter Wong. Wong’s offices were allegedly last month raided by FBI agents.

Our calls and messages to DBI have not been returned. The FBI refused to comment.

Update, Feb. 6: John Murray, a DBI spokesman, returned our call. He confirmed that visitors from the FBI dropped by the Department of Building Inspection on Wednesday.

“We intend to cooperate with the investigation.”

How many FBI agents dropped by? “No comment.”

How long were they there? “No comment.”

Did they explain what they were looking for? “No comment.”

Do you know if they found what they were after? “No comment.”

Julian Mark contributed reporting.