I cant understand UK CAA declaration that the incident is investigated by Czech CAA. It is not correct.
In the Czech Republic, local CAA (ÚCL Úřad pro civilní letectví) is the authority for state supervision under civil aviation. The are not allowed to provide any investigation of incidents. Their speaker, Mr. Hezký, declared for media:
"We are in contact with UK CAA that grounded the carrier and which is solving the event. We are trying for cooperation but it is rather giving informations and consultations from our side, in other way we are involved very little. We are not investigating the incident, we have no right to do it."
For investigation of air incidents and accidents ÚZPLN (Ústav pro odborné zjišťování příčin leteckých nehod) is appointed. They investigate evens at Czech territory and air space. According Chicago convention (ICAO), incident and accidents are investigated by the state, at witch territory the event occurs. ÚZPLN don't investigate this British airport incidents.