He said: "They watched from a distance as the woman entered the water by herself to swim. The man was shouting something to her from the sand, but they couldn't hear what it was.
"He said something to her, (but) the woman paid him no attention and the man left. The next thing the other group saw was the woman floating face down in the water.
"Autopsy showed no sign of any violence, no marks, bruises or any other type of marks. Water was found in the lungs."
Man arrested for 'failing to save' Irish tourist who drowned during late-night swim in Lanzarote
"He said something to her, (but) the woman paid him no attention and the man left. The next thing the other group saw was the woman floating face down in the water.
"Autopsy showed no sign of any violence, no marks, bruises or any other type of marks. Water was found in the lungs."
Man arrested for 'failing to save' Irish tourist who drowned during late-night swim in Lanzarote