None of the rights underpinning the Northern Ireland peace process would be affected by Brexit, Leave campaigners said.
The European Convention on Human Rights which introduced the protections has nothing to do with the EU, according to the Leave.EU lobby group.
Many of the court cases addressing issues from Northern Ireland's violent past are inspired by European Convention protections enshrined in the UK's Human Rights Act. Its possible replacement by a British Bill of Rights is expected to be announced in the Queen's Speech at the state opening of Parliament on Wednesday.
Lawyer Niall Murphy from KRW Law said the repeal of the Human Rights Act would be a fundamental attack on the core values of the 1998 Good Friday Agreement which largely ended violence.
But a Leave.EU report said: "The return of sovereignty to the UK could see human rights protections actually improve while our current constitutional arrangements will remain stable."
Leave campaigners noted the peace accord was an international treaty signed by the governments of the Republic of Ireland and the UK.
The agreement sets out the basis for powersharing and formalises entitlements relating to culture and citizenship.
The report said: "None of the policies, legislation, rights or relationships which underpin the peace process are dependent upon the EU and they will not be affected by Brexit."
It said the EU did not have significant input into negotiations prior to the agreement or the agreement itself. "The USA has been far more influential during various stages of the peace process."