This is something detectives of the likes of Sherlock Holmes and Byomkesh Bakshi could never come across but with the phenomenon of the Internet, modern sleuths are increasingly investigating a number of "online infidelity" cases in the country.

Gone are the days when one had to leave the home to find a partner as the Internet brings the world right into bedrooms fracturing the personal relationships due to virtual affairs which extend offline in many cases.

"The online infidelity cases coming to us have increased many fold in the last some years. I have come across cases of multiple affairs due to Internet," says Kunwar Vikram Singh, head of a private detective agency in Delhi.

He says his company receives a lot of requests from people who want to break into personal computers and laptops of their partners as they suspect them of having an affair.

Head of another detective agency, Rajeev George gives the latest example of a cyber affair.

"A housewife came to us some days ago asking us to follow her husband to Bangkok. She had checked his emails and was sure of his affair. We followed him and gave her the evidence she needed," he says.

"Many of these online affairs extend to offline space and the lovers do meet up. The increasing number of dating and friendship websites are a proof of it," he adds.

While Singh does not encourage hacking of passwords to catch the culprit, George says they have used special softwares to track the culprit in some cases.

"We focus on psychoanalysis of the person. There is certain type of behaviour that a person shows while having an extra-marital affair. We train the victim to notice those things," says Singh.

In some cases, he says, there have been people, especially women, living outside India who have sought their services to find credentials of Indian people they came in contact through Internet.

"In many cases we have found that the guy is already married," says Singh. .

Psychiatrist Sanjay Chugh says cyber affairs result from an unhappy marriage. While some people attempt to repair their relation in a positive way, others resort to extramarital affairs.

"There is anonymity in an online affair and the danger of being caught is less. Some stay happy with virtual affairs but some take it forward as well," says Chugh.

In most of such cases, heartbreak and divorce is the result of the affair if another partner catches the guilty.

"Electronic evidence is valid as proof in the court and we need to prove that the email address belongs to the accused. Incase of a fake email, we take help of the IP address," says Osama Suhail, a Delhi-based divorce lawyer.

Cyber laws expert Pavan Duggal says it all starts with flirting online which often manifests into chat addiction.

"The partner becomes so addicted that he or she starts ignoring marital obligations. This trend is increasing in India," he says.

Virtual infidelity is not covered by cyber laws in India. Chugh has a word of advice for those who resort to online infidelity.

"Most people are not serious in such affairs and its better to devote time and repair the marriage rather than staying in a platonic world," he says.