Facebook has been cited as a reason for a third of broken marriages last year and is increasingly being used as a source of evidence in divorce cases.
A law firm called Divorce-Online said that 33 per cent of the 5,000 behaviour-based divorce petitions filed with the firm in the past year mentioned the site.
"Facebook has become the primary method for communicating with friends for many people," the Daily Mail quoted Mark Keenan, managing director of Divorce-Online, as saying.
"People contact ex-partners and the messages start as innocent, but lead to trouble. If someone wants to have an affair or flirt with the opposite sex then it's the easiest place to do it," he said.
The most common reasons for Facebook causing problems in relationships were a spouse finding flirty messages, photos of their partner at a party they did not know about or with someone they should not have been with.
"If you are keeping things from your partner, Facebook makes it so much easier for them to find out," Anne-Marie Hutchinson, of Dawson Cornwell Solicitors said.
Hutchinson said that the site could also be used as evidence of unreasonable behaviour.
"If you are complaining that they have a drinking problem and they have posted statuses about going out on the razzle... that could be used," she added