Amazon may share its name with mythology's greatest female warriors, but the world's largest online retailer employs just 18 women among its 120 most senior managers, and none of them report directly to the boss.

Amazon's founder, chief executive and chairman, Jeff Bezos, runs the company through a select all-male group of 12, known internally as the S Team (Senior Team), who have a direct line to him. And the S Team themselves seem reluctant to employ women, according to a leak from an internal directory.

Including those who report directly to the S Team, there are 132 staff in total in the top two tiers at Amazon. But 13 of these are "executive assistants" and all are women. Out of the 119 senior managers, just 18 are female – 15% of the total – according to information compiled by an Amazon employee in Europe. There are two women on the Amazon board, both non-executive directors.

"At Amazon there is a strong feeling that there is a glass ceiling for women who want to progress above senior manager or director level," said the source, who asked not to be named.

"These statistics show that despite surviving as a company by constantly adapting and innovating, Amazon fails to address its burgeoning issue of workplace inequality. Of Jeff Bezos' 12 direct reports, none are female.

"Amazon has a problem with women, and it needs to change."

When Bezos, who is married to the author MacKenzie Bezos, was looking for a wife, "The number-one criterion was that I wanted a woman who could get me out of a third-world prison," he told Wired magazine in 1999, saying that his favoured quality was resourcefulness.

But his views on suitable marriage candidates are at odds with the company's approach to women as employees.

The most senior woman in Amazon is Shelley Reynolds, who acts as controller and principal accounting officer, and is named as a member of the 10-strong team of company officers in the annual report. But the internal directory lists her as reporting directly to the chief financial officer, Tom Szkutak, not to Bezos. The information on Amazon's top team comes from Phone Tool, a directory with a page for each member of staff, giving their name, job title and direct reports.

In the UK, managing director Christopher North is listed as having five direct reports, of whom two are women. One is his assistant, and the other, director of media Rakhi Parekh, is due to leave Amazon in the coming weeks. The only other woman in the top management team for the UK is human resources director Laurie Arnold, but she is not listed as reporting directly to North.

The senior vice-president of business development, Jeff Blackburn, has 10 managers reporting directly to him but none of those listed are women. The same appears to be true for Amazon web services senior vice-president, Andrew Jassy, who is listed as employing nine managers, all male.

The head of human resources, Tony Galbato, appears to be the most female-friendly S Team member, with seven women managers among his 13 direct reports, many of them working in recruitment.

Daisy Sands, head of policy at the Fawcett Society, which campaigns for equality, said: "Across the UK today, only 35% of senior managers are women. Amazon makes even this paltry record look glowing. Excluding women from these influential roles means missing out on the substantial benefits that their greater involvement would bring.

"Evidence shows that more women in senior management leads to better corporate performance, a boost to the bottom line, and allows businesses to tap into new insights about their customers. Amazon must take firm action to ensure that it enables women to flourish at all levels of the company."

Gender balance is an issue across the technology sector, despite Yahoo boss Marissa Mayer and Facebook's chief operating officer Sheryl Sandberg's arrival in Silicon Valley's upper echelons.

Google has no women among its executive officers and one among the seven-strong second tier senior leadership team. Apple has an all-male team reporting to its chief executive, Tim Cook, although that will change next week with the arrival of Burberry boss Angela Ahrendts to head its retail operations. Microsoft scores higher – of 12 executives who report to Satya Nadella, two are women.

Amazon said: "We have many women in leadership roles across our global organisation, including two members of our board, and have recently been recognised by 2020 Women on Boards and ranked the number three employer by Woman Engineer Magazine."