Spanish nationals David Hernandes Gasulla and Martha Miguel, Hong Kong citizen Tommy Lam Wai Yin, and Malaysian Armilla Alihassan went missing in their small boat on May 2 in waters off the northern tip of Borneo island.
But Malaysian coast guard and naval ships conducting a search discovered them aboard Vietnamese fishing trawlers today morning during an inspection of the vessels, the coast guard said.
"All four missing people are alive. They are on board some Vietnamese fishing trawlers on the high seas," coast guard chief Ahmad Puzi told AFP.
No other information on the foursome's ordeal or how they ended up on the Vietnamese ships was released immediately.
Malaysian fishermen over the weekend recovered an engine entangled in their net that was believed to be from the missing vessel, prompting fears that the boat had sunk.