The champion free diver Natalia Molchanova was giving private instruction to at least two inexperienced divers when she failed to surface from a dive Sunday, according to her son, Alexey.
Ms. Molchanova, 53, is presumed dead, having been missing for four days in the Balearic Sea off the eastern coast of Spain. Underwater search efforts were halted Wednesday; Spain’s Civil Guard said it would continue surface searches through Sunday.
Mr. Molchanov on Thursday provided new details of the circumstances surrounding the incident after news reports in Spain seemed to contradict some of what he and the global federation for free diving, known as AIDA, originally described Tuesday.