Facebook is using a piece of software which screens it users’ conversations for criminal activity and suspicious behaviour, The Telegraph said, citing a report.

The social network uses the technology to monitor chats for certain phrases and vulgar words which may indicate something is wrong with the exchange.

Depending on the language, suspicious exchanges will be reported to police, Facebook’s chief security officer, Joe Sullivan, has told Reuters.

The software pays more attention to conversations between people who do not have regular interaction.

If a chat is considered suspect in any way, it is reported to a Facebook security staff member, who will then make a judgment on whether the police should be called.

According to the Reuters report, at least one child predator has been caught and brought to trial as a direct result of the software.

A Facebook spokesman said: “We’ve never wanted to set up an environment where we have employees looking at private communications, so it’s really important that we use technology that has a very low false-positive rate.”

According to Facebook’s page focused on how it works with law enforcement agencies, the social network says it will share information about its users when it believes it is necessary to prevent fraud.