Mystery surrounds reports of the death of a Russian gas oligarch and his family inside their Spanish mansion.

Investigators are reportedly trying to figure out whether the incident was a domestic murder-suicide or an organized hit. Their bodies were discovered just one day after another Russian gas boss was found dead alongside his own family in Moscow, in similar circumstances.

Spanish news website El Punt Avui reported the bodies of Sergey Protosenya and his wife and daughter were found on Tuesday, April 19, at their home in the seaside resort of Lloret de Mar in Catalonia.