NEO-NAZIS are flagrantly selling white supremacist merchandise for kids and grown-ups on Facebook and Instagram despite being outed in the past.

Children's t-shirts bearing slogans like "white baby – the future of our race" and magazines promoting Nazi ideology are available to buy on the social networks, according to HuffPost.

Facebook had let a prominent Russian neo-Nazi clothing label, White Rex, profit from its platform for at least three years before removing it last month – during that period it had gained almost 13,000 followers.

But its Instagram account went untouched.

Other extremist brands on Facebook included Ukraine's Sva Stone, Germany's Ansgar Aryan and Pride France, some of which have been banned in the past but popped up again having evaded Facebook's moderation system.

One of the brands, Sva Stone, told HuffPost “We have good relationship with Facebook”.

"We previously unpublished the White Rex Facebook Page for violating our Community Standards for Hate Speech. Sometimes when we take down a Page, group or Instagram account for violating our standards, we see new ones set up, oftentimes for the same purpose," a Facebook spokesperson said in an email statement.

"The three Pages and the Instagram account have now been removed."

The ongoing appearance of neo-Nazi and white nationalist merchandise on Facebook again brings to light the issues the platform is facing with extremist content.

It has drawn criticism from MPs in the UK and US lawmakers in the past for failing to take down Jihadi material.

And the company's muddled stance on content removal – as evidenced by CEO Mark Zuckerberg's statement that Holocaust deniers shouldn't be removed from Facebook because they're not "intentionally getting it wrong" – has only made things worse.

Zuck later clarified that his company's aim is "not to prevent anyone from saying something untrue -- but to stop fake news and misinformation spreading across our services."

But Facebook isn't the only web giant making a royal mess of moderation.

Earlier today, it was revealed that Amazon is removing Nazi items (including swastika jewellery and burning cross onesies for kids) after profiting off them for years.