Shell says the security breach does not pose a risk to its employees
Oil giant Royal Dutch Shell has suffered a security breach with contact details of 170,000 employees and contractors available on the internet.
A note with the data said it had been leaked by a group of workers concerned at some Shell's practices, suggesting campaigners infiltrated the company.
But Shell has said it does not believe this version of events.
It says the contact details do not include any home addresses and do not pose any risk to its employees.
The details - which include names, office telephone numbers and post codes of employees worldwide - have been e-mailed to environmental and human rights groups.
In some cases, they reveal private details such as home phone numbers.