Northern Ireland has failed to establish the truth about abuses committed during its civil unrest and as a result will struggle to move forward, Amnesty International warned on Thursday.

The rights group said too many questions remained about the murders and attacks committed during the so-called Troubles in the 1970s, 1980s and 1990s, in which more than 3,000 people died.

Amnesty blames a lack of political will, which in the case of the British government could be "because human rights violations by state actors would also come under scrutiny".

The conflict, between Catholic republican communities who wanted Northern Ireland to become part of Ireland and Protestants who wanted to stay part of Britain, was largely brought to an end under a 1998 peace deal.

Since then police in the British-controlled province have undertaken a series of historical investigations, coroners have held inquests for individual deaths during the violence and a number of public enquiries have been held.

But Amnesty says this is not enough, calling for a single investigative body to look at patterns of abuse by paramilitaries and state actors, as well as incidents of injury and torture which are not currently being looked into.

"The lack of political will to address the past remains the greatest obstacle to establishing a single comprehensive mechanism in Northern Ireland," the 78-page report said.

"Without the truth, however, Northern Ireland's past will continue to cast a long, damaging shadow over its present and its future."

A spokeswoman for the Northern Ireland Office said it would "take time to consider the contents of this report".

In a speech last week, Northern Ireland Secretary Theresa Villiers said: "I am sure that no one here would doubt that the legacy of the Troubles has a continuing impact in modern Northern Ireland."

She added: "The allegation that nothing's happening on the past isn't true. But of course there is no so-called over-arching 'process' on the past and little consensus on what that should be."

She welcomed the new all-party group set up earlier this year to examine some of the most divisive issues in the province, including parades "and related matters stemming from the past", as a way to ease community tensions.

But Villiers warned that any recommendations "must have regard to the fiscal position" of Britain, namely its austerity drive intended to reduce the budget deficit.

And she added: "We will not be party to attempts to re-write history by legitimising terrorism."