Mrs Searle's body was found in the garden of the couple's property in the hamlet of Les Pesquiès, with severe wounds to her head.
Mr Searle's body was found inside their home, about an hour north of Toulouse.
Police were alerted to the incident by a neighbour who had gone to check on them when they failed to turn up for a planned dog walk.
Post-mortem examinations confirmed Mrs Searle suffered "multiple blows to the head with a blunt and sharp-edged object" while Mr Searle died from hanging.
Mrs Searle, 56, grew up in Eyemouth in the Scottish Borders, and Mr Searle, 62, was originally from England.
They previously lived in Musselburgh, near Edinburgh, and married in France in 2023.
Prosecutors said they had lived in the Aveyron region for five years.
According to his LinkedIn page, Mr Searle previously worked in financial crime prevention at companies including Standard Life and Barclays Bank.