Most workers who cost their company hundreds of thousands of pounds are likely to expect a sharp rebuke from the boss – particularly in the charged atmosphere of a trading floor.

But one employee at BNP Paribas was left so traumatised after an outburst by their manager following an apparent mistake that they labelled it “emotional terrorism” which left them with a “feeling of waterboarding”.

In a sign that even some of the most high-pressure workplaces are being forced to ditch the old-fashioned dressing-down, BNP fired the manager, Omar Alami, and he is now suing for unfair dismissal.

The banker, who earned around £1m a year running a trading desk at BNP, is said to have described his unfortunate subordinate as “useless” and “incompetent” in front of colleagues over a potential €800,000 (£666,000) mistake which turned out to be a false alarm. 

Mr Alami denies the accusations and is claiming $4m in compensation for unfair dismissal. 

He told a Paris employment tribunal that his response to his colleague who made the mistake was merely “lively”, and that claims from others were anonymous so are difficult to counter. 

He said: “I was never humiliating, I was never insulting or aggressive.”

The Paris-based financier found a new job within a year of his dismissal, but said he earns 60pc less than he previously did and has to spend 60pc less time with his family as the job is in Switzerland rather than France.

Aurelie Fournier, a lawyer acting for BNP, admitted that the bank had noticed issues about Mr Alami’s communication style and sent him for coaching lessons. 

However, she said that it did not realise the extent of the problem until people complained. The colleague who said he was verbally attacked allegedly had to be put on sick leave for two weeks and came into the office in tears.

“It’s quite rare for people on trading floors to speak up,” Ms Fournier told judges. 

The case is the latest lawsuit revolving around toxic workplace behaviour in the finance industry.

In a separate London case, a UBS trader has claimed that the Swiss bank has a “toxic” work environment where people shout at staff across the trading floor. The bank’s lawyers suggested that this kind of pressured atmosphere “is the unavoidable reality of the work of a City trader”. 

A former Swiss ‘banker of the year’ was also jailed last week for claiming nearly 200,000 Swiss francs on expenses to cover his visits to strip clubs.

The 65-year-old had told a court earlier this year how a 700 franc dinner he had with a woman he met on dating app Tinder was justified because he was considering her for a job, and a trip to Australia took place because he needed to examine the country’s cash machines.

The court also heard that bills he expensed included almost 4,000 francs for the repair of a hotel room at the five-star Zurich Park Hyatt that was damaged during a “massive row” he had with a strip club dancer he was dating.

It is not just banks facing questions over their behaviour. 

Earlier this year sources told The Telegraph that Lloyd’s of London, the world’s oldest insurance market, was preparing to issue a member with a fine or ban for behaviour which involved a “systematic campaign of bullying against a junior employee over a number of years”.

The employee used to work for Atrium Underwriters, which was hit with a record £1m fine earlier this year after it was found to have tolerated bullying and an annual “boys’ night out” involving initiation games, heavy drinking and the harassment of female staff in the years leading up to 2018. 

The disclosure came as a blow to the London insurance market, which has tried to clean up its image in recent years following claims of sexual harassment which surfaced in 2019. 

Lloyd’s only allowed women onto its dealing floor in 1973.

A BNP Paribas spokesman said the bank “does not tolerate behaviour contrary to the respect and dignity of the individual, at all levels of the organisation” and has systems in place to detect and combat harassment. 

“In this case, the company has taken all measures to protect its employees in accordance with the group’s procedures”. 

Mr Alami could not be reached for comment. A ruling is expected on May 17.