Mohamed Samak, 44, claimed to detectives that his wife Joanne, 49, had knifed herself in the chest and stomach at their home in Droitwich Spa, Worcestershire.
Joanne Shaw, 35, was killed last Sunday by her violent ex Ryan Kelly, 41, in a suspected murder-suicide when he forced his way into the house in Bristol and set off the blast.
Joanne Shaw, 35, had left her violent ex-partner Ryan Kelly, 41, for her own safety and moved back in with her family, calling police over his behaviour multiple times.
Joanne Shaw, 35, sent the youngster to play outside on the trampoline when a serious argument began in the early hours of Sunday morning, a neighbour said.