Johor Malaysian Maritime Enforcement Agency (MMEA) director First Admiral Nurul Hizam Zakaria said a tugboat en route from Indonesia to Thailand found Grodem, 35, floating in full diving suit and equipment at 8.15am in the waters of Tanjung Sedili, Kota Tinggi.

“She was then transferred to an MMEA helicopter and taken to Mersing for treatment.

“The search for the remaining victims is ongoing,” he told reporters at the Mersing public jetty.

The three divers still missing have been identified as Alexia Alexandra, 18, Adrian Peter, 46, and his son Nathen Renze, 14.

Nurul Hizam said the sea search covered an area of 107 nautical miles while the air search covered 270 nautical miles, focusing on the southern part of the scene.

“The victim drifted south and was found in the waters of Tanjung Sedili. She is in stable condition and sustained no serious injuries,” he said.

He said the Indonesian National Search and Relief Agency and Singapore authorities were also informed of the incident involving the divers who were believed to be drifting towards the south of the island.

The marine department had also issued a notice to ships in the location to assist the victims if they were found.

Boat skipper detained

Earlier, police said they had detained the skipper of the boat boarded by the four divers after he tested positive for drugs.

Johor police chief Kamarul Zaman Mamat said the man, in his 20s, had been initially called in to give his statement.

“We conducted a urine test and found he tested positive for drugs. We will detain him until our investigation is completed,” he told reporters at the Mersing jetty.

Kamarul Zaman said the boat skipper was detained at the district police headquarters at about 11.30pm yesterday and was being investigated under Section 15 (1) of the Dangerous Drugs Act.

Asked if there was an element of negligence in the incident involving the foreign divers, he said his team was investigating all aspects.