A woman has died after bags thought to contain cocaine broke in her stomach following a flight back to the UK.
South Wales Police said earlier they were looking for David Case
Nicola Jayne Last, 40, from Barry, Vale of Glamorgan, died in hospital on Sunday, the day after she was admitted for a suspected drugs overdose.
South Wales Police later arrested a man and then took him to hospital for "immediate medical treatment".
Detectives said he was arrested in the Cardiff area in connection with drug-related offences.
Ms Last was admitted to Llandough Hospital, near Cardiff, on Saturday morning.
Police said the hospital found that her stomach contained "a large number of small bags containing what is believed to be cocaine".
Some of these bags had broken, and she died at 0640 BST on Sunday.
No more details were available of where Ms Last had been recently, but police said she and a man had flown into the UK "from abroad".
Det Supt Simon Clarke said of the arrested man: "We had real concerns for this man's wellbeing.
"Following extensive enquiries, working with other agencies and the public, he has been found and taken for immediate medical treatment.
"This is now the very beginning of the investigation on the circumstances surrounding the tragic death of Nicola Last."
Earlier, police had said they were looking for a 43-year-old man who they thought may have swallowed drugs.
Police had named him as David Case, who had lived at addresses in the Cardiff and Barry areas. They said their main concern was that Mr Case was "fit and well".
Anyone with information can contact Barry CID on 01446 734451 or Crimestopppers anonymously on 0800 555111.