The stepfather and son had rowed furiously after the wi-fi was turned off as Duanjan screamed obscenities and smashed up the house last Thursday.

Mr Khamruang had been forced to hit the younger man to get him to sober up, but the pair went to bed and he thought that would be the end of it.

Mrs Duanjan said she discovered the poison when she went to collect water for cooking rice in the morning.