I can't find any mention of this account on their website, but I did find this very old FT article
I've never heard of this before. I'd certainly make sure that you are only investing in deposit accounts protected by the FSCS. This all sounds very reminiscent of a credit union named DotCommUnity that tried to push people into investment products and then went insolvent shortly afterwards.
Edit: Found the Government description of the scheme here
Subject to certain conditions, CITR is available to an
individual or company
who invests (by way of loan, securities or share capital) - see CITM4005,
in an accredited Community Development Finance Institution (CDFI) - see CITM2005
And from here
An investment is a qualifying investment if ... there are no arrangements concerning protection of the investor against risks relating to the investment
So your capital is at risk.