Private investigators are now being used more frequently as spouses try to catch their loved ones cheating, according to research released today.

Almost twice as many women than men used the services in 2007 with more than two thirds of divorce lawyers reporting at least one instance of a client using a private investigator. The research, compiled by Grant Thornton’s Forensic and Investigation Services practice, also showed that extra-marital affairs were still the main cited reasons given by couples seeking a divorce.

During 2007, just under a third of marriages broke down due to one partner being unfaithful. In more than three-quarters of those cases it was the husband caught cheating, a significant increase on the 69% from 2006.

Will Davies, a partner at Grant Thornton’s in Cardiff, said, “Marriages are meant to be built on trust, yet this figure shows this is not always the case. While hiring a private investigator might seem like an extreme length to go to, people just want to know the truth, even if it hurts.”

Mid-life crises were the second most common cause of a divorce with 14% of citations, seven times more than last year.

In 93% of cases it was the husband’s mid-life crisis that caused the problems. Family strains were the third most common reason with 11% of citations.

The English and Welsh divorce courts are still thought to favor women. Research showed that 94% of lawyers surveyed thought women petitioning for divorce would get the more favorable settlement.