Police have named a soldier who died during an exercise at an army barracks.
Pte Williams died in Salisbury District Hospital
Private Gavin Williams, 22, of Hengoed, Caerphilly, south Wales, collapsed at about midday on Monday at Lucknow Barracks in Tidworth, Wiltshire.
Five servicemen from his regiment - the 2nd Battalion Royal Welsh - have been arrested on suspicion of manslaughter.
Police arrested four - aged 44, 35, 31 and 28 - on Monday and have been given an extra 12 hours to question them. A 29-year-old was arrested on Tuesday.
All five are being held at Salisbury.
Ambulance crews were called to the scene and a spokeswoman for Wiltshire Ambulance Trust said that the man appeared "hot and agitated".
But she would not comment on reports that he had suffered heat exhaustion.
Pte Williams later died in Salisbury District Hospital.
The 2nd Battalion The Royal Welsh recruits was founded 300 years ago and has 600 members based at Lucknow Barracks in Tidworth.
A Welsh flag was being flown at half-mast at the entrance to the barracks on Tuesday.