In 2022, Wells Fargo said it had adopted a hybrid flexible working model with staff permitted to work from home some of the time.

Some large companies have been using increasingly sophisticated tools to monitor employees since remote work expanded during the Covid pandemic.

Such services can track keystrokes and eye movements, take screenshots and log which websites are visited.

But technology has also evolved to evade the surveillance, including so-called “mouse jigglers” which are aimed at making computers appear to be in active use which are widely available.

According to Amazon, where they can be found for less than $10, thousands have been sold in the last month.

Bloomberg, which first reported the move based on a filing Wells Fargo made to the US Financial Industry Regulatory Authority, said that more than a dozen people had been affected.

The BBC has confirmed six instances in which staff had been discharged after review, and one case in which a person resigned voluntarily after being confronted with the claims.

Many of them had worked for Wells Fargo for less than five years.

Many firms, especially in the financial industry, are pushing staff to return to the office.

Remote work has remained popular since the pandemic but numbers have been drifting lower.

In the US, just under 27% of paid days last month were work-from-home days, compared with more than 60% at the height of the pandemic in 2020, according to research by professors at the Instituto Tecnológico Autónomo de México (ITAM) Business School, Stanford and University of Chicago.

As of this spring, about 13% of full-time employees in the US were fully remote, and another 26% enjoyed a hybrid arrangement, according to the researchers.