A black former Facebook employee has accused the social network of having a "black people problem" in a memo about his time at the company.

Mark Luckie published a note he circulated inside Facebook shortly before his last day at the company earlier this month, in which he claimed he had witnessed a range of discrimination issues.

He claimed that while Facebook speaks of creating a community based on inclusion, he did not experience that while working for the firm.

"Facebook has a black people problem. One of the platform's most engaged demographics and an unmatched cultural trendsetter is having their community divided by the actions and inaction of the company. This loss is a direct reflection of the staffing and treatment of many of its black employees," he said.

"In my time at the company, I've heard far too many stories from black employees of a colleague or manager calling them 'hostile' or 'aggressive' for simply sharing their thoughts in a manner not dissimilar from their non-black team members."

He added that he believed black people remained underrepresented at the company.

"In some buildings, there are more Black Lives Matter posters than there are actual black people. Facebook can't claim that it is connecting communities if those communities aren't represented proportionately in its staffing," he said.

In its most recent diversity report, published in July, Facebook said the proportion of black employees at the company had risen from 2% to 4%, but the number of black employees in technical roles remained at 1% and the figure in leadership roles was 2%.

Mr Luckie said his experiences meant he had "lost the will and the desire to advocate on behalf of Facebook".

In response, Facebook said it was continuously working to be inclusive.

"Over the last few years, we've been working diligently to increase the range of perspectives among those who build our products and serve the people who use them throughout the world," a company spokeswoman said.

"The growth in representation of people from more diverse groups, working in many different functions across the company, is a key driver of our ability to succeed.

"We want to fully support all employees when there are issues reported and when there may be micro-behaviours that add up. We are going to keep doing all we can to be a truly inclusive company."

Mr Luckie welcomed the response, before revealing in a follow-up Twitter post that he had also received a message from Facebook executive Ime Archibong on the issue.

"I appreciate Facebook's response to my post calling out discrimination at the company," Mr Luckie said.

"However, the tone is noticeably different from the only response I received from senior leadership after sharing the post internally."

Mr Archibong - who is also black - described Mr Luckie's note as "pretty self-serving and disingenuous", adding that he was "confused and pretty hurt" by it.

He also responded on Twitter, saying he was disappointed Mr Luckie had chosen to share "private messages without permission in a public forum".

"There's always more work to be done - and all the folks who have been here for several years doing this work have never been shy about saying that," he added.

"As in life, we all have diverse experiences and I can't speak for your personal experience at FB - but your experience is not my experience and not that of many others here. For any of us to try and claim our experience is representative of all experiences here is simply false."

By Martyn Landi