Kenga argued that the death of his firstborn son became an excuse for his execution adding that the real cause of the attack was a family land tussle.
He said some family members wanted to sell part of a 10-acre ancestral land against his wish and plotted to kill him so they could continue with the transaction.
"My father had two wives. Some of my young brothers want to sell part of the land even now that I am away at the rescue centre in Malindi," he said.
Kenga claimed his wife abandoned him after staying in the hospital for two weeks, leaving him to fend for his two sons.
Mr Kenga's uncle, Ibrahim Masha said Kenga had a long-running dispute with his young brothers over the ancestral land.
"It was surprising because hippos attack people so often on river Sabaki. Recently, a hippo attacked another person," Masha noted.
HYO programmes officer Julius Wanyama, who accompanied Mr Kenga to the police station, said six people have recorded statements in connection with the attack while another suspect was on the run.
He said in Malindi, HYO was following up 21 cases of brutal attacks linked to witchcraft while three others were in court.
Mr Wanyama told the police to treat these cases seriously just like cases involving sexual and gender-based violence to guarantee victims justice.
"It's high time cases of killings and attacks targeting the elderly suspected to be witches were treated more seriously and consistently in terms of follow-up, documentation, and coordination," he said.
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