Searches carried out at 40 premises over the last two weeks also uncovered 7,000 items of software for further examination, the police said.

The raids were led by the Police Service of Northern Ireland Care Unit.

The police said they would not disclose how many people are under scrutiny or their exact location in case it jeopardised prosecution hopes.

We have then sought to prioritise those individuals identified, looking first at those who are in a position of trust or whose work brings them into contact with children

PSNI Inspector David McConville

But officers are focusing first on those whose work brings them into contact with children and young people.

Inspector David McConville said: "We view the use of child pornography as serious criminal behaviour and the PSNI Care Unit are proactively pursuing this kind of crime.

"Our recent searches have thrown up a very large amount of evidence to be thoroughly and methodically analysed and we have now entered that phase of the investigation."

Detectives have now begun linking names to the equipment seized.

"We have then sought to prioritise those individuals identified, looking first at those who are in a position of trust or whose work brings them into contact with children, no matter who their employer," Inspector McConville said.

"To avoid making mistakes these processes have to move forward methodically and sensitively.

"At this stage it would prejudice the outcome of continuing inquiries being made by police and endanger the likelihood of successful prosecutions to reveal the precise scale and location of those who are under investigation.

"However, I can say that our inquiries relate to all sections of the community.

"No distribution pattern has been established as yet."