Goldman Sachs Group Inc. is dismissing about 20 analysts globally in offices including London and New York after discovering they had breached rules on internal training tests, said people familiar with the matter.

The analysts, who had been working in the investment bank’s securities division, have either already been dismissed or are in the process of leaving the bank, said the people, who asked not to be identified as the matter is private.

“This conduct was not just a clear violation of the rules, but completely inconsistent with the values we foster at the firm,” said Sebastian Howell, a Goldman Sachs spokesman in London, who said he couldn’t comment further.

Bankers throughout Wall Street often assist each other on basic training and compliance tests because these are seen as time consuming and repetitive, according to separate people with knowledge of the process. Investment banks have started taking strict measures to prevent this from happening in recent years amid increasing scrutiny from regulators.

Goldman Sachs is among the most selective employers on Wall Street. Last year, the bank hired just 3 percent of 267,000 applicants, and Chief Executive Officer Lloyd C. Blankfein has called his firm“the employer of choice in our industry.” Fortune magazine named Goldman Sachs one of the 100 best companies to work for, a citation it has received every year since the list began in 1984, according to a presentation given by Blankfein in February.

The firings come the same week that the New York-based firm reported quarterly earnings that fell short of analysts’ estimates for the first time in four years.