A man awaiting trial accused of the killing of his fiancee 14 years ago has been seized by police accused of murdering his wife and two children.

Taxi driver Alexander da Silva , 49, from Rio de Janeiro, Brazil, was arrested on Friday, 17th February.

The night before he had, reports local media, drugged his wife and children – including an 11-monnth-old baby – with melatonin, often found in sleeping aids.

He shot wife Andrea Cabral Pinheiro, 37, once in the head then executed his 12-year-old daughter Maria Eduarda Fernandes Affonso da Silva with three bullets.

His infant son – Matheus Alexander Cabral Pinheiro da Silva – was choked to death in his sleep, reports local media.

Da Silva fled the family home but was grabbed and tied up by neighbours when he returned the next day.

He was then arrested and taken to the Lourenco Jorge Municipal Hospital, where he was treated for minor injuries.

After he was discharged, police brought him to the Capital Homicide Police Department (DHC).

Police Chief Wilson Palermo said: “The expertise identified that there was use of melatonin, which is a substance whose purpose is to induce sleep.

“So, this was essential for him to be able to commit the crime.

“We have no doubt that he was really the perpetrator of the crime, thanks to the testimony of other witnesses.

“He has not shown any regrets so far. He is cold, calm.

“We will still have the opportunity to listen better, calmly and we will be able to resolve all the details.”

Bizarrely police say da Silva is also awaiting trial for allegedly stabbing his former fiancee Tatiana Rosa de Franca, 27, to death on 25th July, 2009.

The trial was reportedly postponed several times because of Covid-19 restrictions.