Few Russian addresses have received as much attention as 55 Savushkina Street. The grey, four-storey office block in St Petersburg's northwestern suburbs seems almost undeserving of the interest. But the souls inside, busy with pro-Kremlin internet manipulation since 2011, have ensured their building will stay in the headlines for some time to come.

An investigation has revealed more intimate details about the office, known colloquially as “the troll farm.” The report, published on Tuesday by the business portal RBC, suggests that the organisation played a role in the US election campaign and its aftermath, organising as many as 40 US rallies and protests.

The report identifies 120 different groups and social media accounts used by trolls over 2016-2017. “The farm,” it suggests, concentrated on divisive social issues for the US, particularly civil rights.

The report describes a rally held in Charlotte on 22 October 2016, ostensibly against police violence. The event was held in the name of “BlackMatterUS,” and it seems probable many of the activists who took part did not understand the rally was unconnected with Black Lives Matter. Or, indeed, that the entire operation was being directed from St Petersburg.

Facebook advertising campaigns also focused on divisive messages, the report says. The US tech giant has already confirmed 55 Savushkina Street was responsible for buying $100,000 (£75,000) worth of pre-election posts, and this report does not add to those numbers.

It reveals details about the organisation’s relatively modest budget. Over two years, “the troll farm” spent $2.2m (£1.7m), the vast majority of which went on wages. For Russia’s second city, the pay was reasonable but not excessive. Wages started at 55,000 rubles (£725) per month for a new hire, rising to 120,000 rubles (£1600) for line managers.

In total, 250 people were employed, with 90 dedicated trolls working on the US election campaign at its peak.

Close scrutiny made the trolling organisation change its methods. Following publication of a long investigation in The New York Times in June 2015, Facebook blocked its accounts. But “the farm” opened new channels and reverted to more sophisticated anonymous protocols. The authors of the report say 55 Savushkina St kept about a million subscribers on various channels even after the main Facebook accounts were closed.

“They’re learning, but only by their mistakes,” Andrey Zakharov, one of the authors of the report, told The Independent. “Their US operations, for example, required total anonymity, but they still fumbled by attaching Russian mobile numbers to their Twitter accounts.”

Russian presidential spokesman Dmitry Peskov has distanced the Kremlin from allegations of interference in the US elections.

“We don’t know who placed the Facebook ads, how they were placed,” he told journalists last month. “The Russian side is not involved in this.”

The report does not contain any smoking gun that might link “the farm” to the Trump campaign. Indeed, its authors suggest that media coverage of the trolls of 55 Savushkina St may be somewhat incommensurate with their real influence. Interest in Russia’s “troll farm” had arguably reached "unhealthy" levels, Mr Zakharov told The Independent.

“You hear very little about the Macedonian bloggers that pumped out fake news in support of Trump, yet their audience was phenomenal,” he said.