Not one of those sources in the Wikipedia article had any evidence other than news articles about one UN committee member saying she saw evidence of it being 1 million people in camps. Not firsthand, just reports.

Every other article on the fact repeats this. Nearly a dozen citations and it's all just news articles about the same story.

I tried searching for the UN committee on racial discrimination tabled documents but couldn't find anything.

Is there any serious estimate of the number of people actually interned in these camps or is it all a game of Chinese whispers (pun not intended)

I have witnessed firsthand how indifferent mainlanders are to these things but think the original comment has merit.

Where's the actual non biased numbers?

Tibet.

Perhaps you intended to respond to a different comment?

Do you think in future you could leave out the "How can anybody not be aware of this?"? It helps nobody. Thanks.

I looked at that page, it doesn't seem to support the claim there are "millions of Muslims in a camp".