Members of the South's Garda Siochana police who leak stories to the media regarding the peace process or paramilitary groups could now face up to five years in prison.
The latest police bill makes it illegal for any officer to speak out about the illegal activities of the IRA and any other organisation which has signed up to the peace process, including political parties.
The move has been strongly criticised by human rights groups.
Section 55 of the Bill warns members and ex-members of the force against disclosing information that 'affects adversely the relations of the Government with any political party, group or institution in Northern Ireland or the Government's ability to promote agreement, advance the peace process or engage in negotiations with regard to Northern Ireland'.
Senior officers in the force expressed concern that the Bill would make it dangerous for them to brief the media.
Human rights organisations said the Bill was a mistake and would not help the cause of the peace process. The Index on Censorship said peace processes could not be based on preventing the truth.
Ursula Owen, the editor of the Index's magazine, said: 'From what we know of other peace processes around the world, such as South Africa and Chile, it is that they only work when they are based on truth.
'A peace process based on truth being covered up would be catastrophic.'
She cited the work of the murdered Dublin journalist Veronica Guerin, who used Garda sources to expose drug dealers and crime lords. 'Under this legislation police officers would be reluctant to help others like her write stories that are in the public interest,' she said.
Article 19, which also campaigns for the right to free expression, said that the Bill violated the right for the public to information and the rights of whistle-blowers to leak stories in the public interest. The group's spokesman, Morris Lipson, criticised the use of the words 'affects adversely' contained in the section on Northern Ireland.
'The problem here is that the definition is too broad. How do you define if something "affects adversely" the peace process?' he said.
'There is another objection to this Bill, which is that the penalties imposed on whistle-blowers from the force are very, very strong.
'In fact what's needed instead is the introduction of legislation in Ireland to protect the rights of whistle-blowers to leak information when it is in the public interest.' Lipson added.