SAN FRANCISCO (KPIX 5) — The now shuttered Russian consulate perched atop San Francisco’s Pacific Heights neighborhood was a hotbed for espionage and spying, according to a published report.

An online article for Foreign Policy magazine, citing multiple former intelligence officials, said that “’strange activities’ originated far more frequently from the San Francisco consulate than any other Russian diplomatic facility in the United States, including the Russian Embassy in Washington, D.C.”

The consulate was closed by the Trump administration after Russian President Vladimir Putin ordered a drastic reductions in U.S. diplomatic personnel working in his country.

The intrigue ratcheted almost immediately as black smoke began emitting from the San Francisco consulate’s chimney as it appeared documents were being burned.

“We kicked them out for a reason,” said KPIX 5 security analyst Jeff Harp. “We didn’t just kick them out because we didn’t like what the cook was doing.”

The consulate officially was supposed to be handling passports and visas. But the consulate’s panoramic view of the San Francisco Bay and its location near Silicon Valley made it a haven for spying, according to the Foreign Policy article.

“The Russian consulate in San Francisco has been an active intelligence gathering platform – it’s no secret- for years and years and years,” said Harp, the former agent in charge of the San Francisco FBI office. “This goes back to the days the Presidio was a military operation.”

“There have been some suggestions that maybe they were communicating with boats or other military or intelligence collection or aircraft,” Harp continued. “It’s very possible. It wouldn’t surprise me in the least.”

He said the array of antennas and satellites and electronic transmittal devices on the consulate’s rooftop were not just there to transmit official cables.

“There’s a lot of boxes, a lot of things,” he said. “A lot of communications systems and some of it may be for clandestine purposes, some of it may be for communication purposes – not necessarily spy activity – but you don’t want to let the host government know what your electronic collection capabilities and how you have have it designed.”

The keys to the building were turned to the FBI in September. Harp said it was likely that the agency carefully searched the building.

“To go in there and find a little nugget would be nice, but I think the Russians were probably extremely careful about what they put in and how they pulled it out,” he told KPIX 5.