Dan Ross spent several days in a notoriously grim jail in Coxen Hole on the Honduran island of Roatan before being transferred to a police station following the intervention of British diplomats.
Mr Ross, who holds dual British and Australian nationality, has yet to be charged with any crime but, as a foreigner, the Hondurans consider him a flight risk.
He told police that Mariska Mast collapsed suddenly on his bathroom floor at around 3am last Friday after they had gone out drinking.
After monitoring her condition for two hours with a Korean woman with whom he shared the flat, Mr Ross noticed her breathing had stopped and immediately performed cardiopulmonary resusciation (CPR).
According to British officials, Mr Ross took her to hospital but, unable to converse with Spanish-speaking doctors who signaled that he had to leave, he returned to his home in the island’s West End district.
Finding his housekeeper cleaning up after the incident, he helped her – unaware that Miss Mast had died and that they were removing vital evidence.
Mat Harper, the British Honorary Consul on Roatan, said he was visiting Mr Ross every day with food and reading materials.
He said: “He’s in pretty good shape. He’s being detained as a matter of course as, under Honduran law, he was associated with the woman who died.”
He added: “He’s being held for questioning because the Hondurans want to ascertain exactly what happened that night.”
An autopsy at the weekend was inconclusive but Mr Ross’s fate will become clear at a second hearing when the Hondurans must decide whether to charge or release him.
Mr Ross, who was born in Australia but is understood to have a British mother, had been on Roatan since March. He taught at the British-owned Coconut Tree Divers diving school, where he had completed both his diving and instructor training .
Staff at the school said they were "horrified" by his situation and described Mr Ross as a “great guy”.
A fellow teacher said: “It’s really harsh. In the diving industry, we’re taught to administer CPR and first aid. Dan went into the mode that all of us go into when that happens.”