Proms recording

[Christopher]

Does anyone know what happens to BBC Proms recordings? The BBC link to the Proms concert that I most enjoyed this year is now no longer active (I didn't realise they took them offline). Does one have to request them? Do they become commercially available? Or do they just disappear forever into an archive?!

(The concert in question was actually "Le Concert Spirituel" - music outside the remit of this forum (Striggio, Benevolo etc, I don't suppose anyone has it?!) - but it would be good information to know anyway, as there other concerts I went to whose music was very music within remit and whose performances I would love to revisit!).