The Italian man, identified by lawyers in the case only as Antonio C, was rifling through an old chest of drawers when he made the discovery a few days before Christmas.

Notwithstanding the time that had elapsed since the betrayal, he was so upset that he immediately confronted his wife of 77 years, named Rosa C, and demanded a divorce.

Guilt-stricken, she reportedly confessed everything but could not persuade her husband to reconsider his decision.

According to court papers released in Rome this week, she wrote the letters to her lover during a secret affair in the 1940s.

The discovery of the letters was the final straw for a marriage that had already run into difficulty ten years ago. The husband briefly left their house in Rome and moved in with one of his sons, only to return a few weeks later.

The Italian press attributed the acrimonious split to the couple's southern blood. He is originally from Olbia in Sardinia, while his wife was born in Naples.

The couple met during the 1930s when Antonio was posted as a young Carabinieri officer to Naples.

The case appears to set a new record, at least for the age of the oldest protagonist. The previous oldest couple to divorce were Bertie and Jessie Wood, aged 98, from the UK.

The pair ended their 36-year marriage in 2009 when they were both two years away from their 100th birthdays.

They got married in Elstree, Hertfordshire, in 1972, having both ended previous marriages, before moving to Falmouth, Cornwall, four years later.