All freediving records are now followed by a decompression stop at 6m on pure oxygen (from a tank). If you exclude this, then the last constant weight record (for example) without this was probably Carlos Coste's 105m set around 2005.
I have pioneered the method called 'apnea deco', the concept of going back down immediately after the dive while holding your breath, to do deco without scuba bottles; this does work but is not as effective as doing it with enriched oxygen. It is also extraordinarily unpleasant; often more painful than the deep dive itself.
If the rules disallowed decompression after the dive, then records would have ended around 2005 and any attempt to break them would have resulted in lifelong paralysis, neurological damage, and so on. So, for those of you who (in your mind) think it is cheating to deco after the dive, then for you, records ended in 2005.