BBC Wales picture editor Johanna Powell, 37, from Cardiff, vanished after an incident involving a cruise boat on  the Mekong River near Pak Beng, Laos.
The Foreign Office is working with authorities in the country.
A BBC Wales spokeswoman said: "We are very concerned about our missing colleague and are in contact with the family to offer any support we can."
Ms Powell's family is being provided with consular assistance by the Foreign and Commonwealth Office.
Searches are continuing for a woman who has gone missing in south-east Asia.