Private detective use soars as spouses spy on partners

The number of suspicious partners hiring private investigators to set up honey traps for their spouses surged last year as a string of celebrity divorce cases shone an uncomfortable spotlight on a business that usually remains shrouded in secrecy.

The number of lawyers with clients using private detectives to confirm infidelity was up almost a third on last year, according to research published today by Grant Thornton, with more and more people following in the footsteps of high-profile figures who have turned to "private eyes"for help in establishing whether to end their marriage.

Matthew Mellon, the American banking heir, was cleared of wrong-doing last year after he admitted hiring Active Investigation Services (AIS) to spy on his former wife Tamara Mellon, the founder of Jimmy Choo shoes, before their divorce in 2005. And Ingrid Tarrant, the ex-wife of Who Wants to be A Millionaire? presenter Chris was granted a divorce after private detectives confirmed he had had a 10-year affair with Fiona McKechnie, the deputy head of a primary school.

But solicitors said yesterday that hiring the services of a private investigator was no longer the preserve of the suspicious super-rich. More than two-thirds of leading matrimony lawyers reported they had at least one client last year who paid detectives to spy on a partner – up from 49 per cent of lawyers the previous year and only 19 per cent in 2005. Of those clients, 64 per cent were women.

Andrea McLaren, the head of Grant Thornton's London Matrimonial Practice, said: "Marriages are meant to be built on trust, yet these figures show that is not always the case. While it might seem like an extreme length to go to, people just want to know the truth – even if it hurts."

For the fifth year in a row, extramarital affairs were the main reason cited by couples seeking a divorce. During 2007, 29 per cent of marriages hit the rocks due to one partner being unfaithful, down from 32 per cent in 2006.

Grant Thornton also reported an increase in "shopping for divorce", with 94 per cent saying English courts are the most favourable place in the world for women to reach a beneficialsettlement.

Men would be better off petitioning to end their marriages in South Africa, the US – where, unlike Britain, pre-nuptial agreements are legally binding – or France, where Nicolas Sarkozy and his second wife,Cecilia, were granted a divorce last October, just months before the French President married the former model Carla Bruni.

The figures showed that women still win massively over men in claiming exclusive rights over their pets. In about two-thirds of cases, wives gained sole custody of their pets, compared to only four per cent of husbands.

This trend has come to Britain from the United States, where custody of animals has been a key issue in splits between celebrities. One of the most famous cases concerned the actress Drew Barrymore, who fought with her former husband, Tom Green, over their dog, Flossie, and won her case.