An April Fool's prank tweeted by staff at budget airline Thai Vietjet could lead to criminal charges after an activist lawyer filed a complaint with police alleging it had insulted Thailand's King Maha Vajiralongkorn.

Police will decide later whether to pursue a criminal case under strict "lese majeste" laws - which make defaming the monarchy punishable by up to 15 years in prison - against staff of the airline, an offshoot of Vietnam's Vietjet Aviation JSC...