They were Julius Atsu Akpabla and Juliet Atsufui Akpabla.
He said Madam Afedo on her return did not find the twins behind their plates, and after combing around and not finding them, raised the alarm.
Mr Ntumi said a neighbour directed his flashlight into the concrete water tub for harvesting rain water, at the edge of the house and found the lads under the water.
He said they were rushed to the Sape Agbo Memorial Hospital at Denu where they were pronounced dead on arrival.
Mr Ntumi said their bodies had been deposited at the Ketu-South District Hospital, pending autopsy.