South Wales Police say the 51-year-old man who collapsed in a Pontypridd supermarket on Wednesday is no longer believed to have been the victim of a crime.
He has now been released from hospital, but faces further questions from officers.
The centre of Pontypridd has been cornered-off around Taff Street as an air ambulance landed a short time ago.
South Wales ambulance service confirmed they are attending an incident on Taff Street after receiving a call at 12.36
The following crews are still at the scene: a rapid response vehicle, one emergency ambulance, a Helimed helicopter and a doctor.
Rain clipping the far north through the evening but elsewhere staying dry with some sunny spells.
Public Health Wales figures show 25 more cases of the virus have also been confirmed.
Photos taken on Saturday morning show Roald Dahl Plass strewn with empty beer bottles and discarded canisters of laughing gas.