Triple axe murder-accused Henri van Breda has a form of epilepsy that might explain the "missing" two hours and 40 minutes in his version of events, a neurologist said.
Dr James Butler, who conducted tests on Van Breda, testified for the defence in the Cape Town High Court on Monday, saying the seizure could have caused short-term amnesia.
Van Breda is accused of axing his parents and brother to death and leaving his sister for dead - she ultimately survived - at their luxury De Zalze estate in Stellenbosch.
The state argued earlier that the nearly three hours during which Van Breda claims he was unconscious at the bottom of the stairs was a convenient explanation for a timeline that did not add up.
Two weeks ago, defence counsel Piet Botha said his client had had a fit and had just been diagnosed with juvenile myoclonic epilepsy.
Butler testified on Monday that Van Breda could have had a seizure for half an hour and then experienced two hours and 10 minutes of amnesia thereafter.