i too noticed this going on last week but only realised that the person lying on lounger did not own it when i saw him return to a flat which was obviously not occupied.
the same renters were also very noisy at 3am one morning - but were soon approached by security after which they were not heard from again - dont know whether they were put out or just their last night.
they were in block 35 at time.
i dont know if there is maybe a number to call to repoert noise at this time and maybe someone could post here if there is?
im no prude but there are limits to noise at this time eh.