Cairo: The owner of a pickle plant and his three sons died while cleaning a processing tank inside the facility in a province south of Cairo, local media said.
The incident took place Friday in the factory located in an industrial zone in the southern governorate of Beni Sueif.
Their death was probably due to suffocation caused by a shortage of oxygen during cleaning the tank, news website Al Youm quoted a labour witness as saying.
However, private newspaper Al Watan, citing initial investigations, reported that the four had died of electrocution during their sanitisation of the tank. There has been no official comment on the reports.
Pickles are a popular appetiser in Egypt.