A businessman who played an important role in securing peace in Northern Ireland has died aged 80.
Brendan Duddy acted as a secret back channel link between the IRA and the British government for more than 20 years.
The clandestine connections led to the IRA's 1994 ceasefire and the Good Friday peace agreement four years later.
The contact lasted from the 1970s into the 1990s.
Mr Duddy was the most important link between then British prime minister Margaret Thatcher and the IRA during the 1981 hunger strikes.
Among those to pay tribute were SDLP Foyle Westminster candidate Mark Durkan.
Sinn Féin's Elisha McCallion said she was shocked and saddened.
"Brendan was a key figure in the business life of Derry for decades and was widely respected across the city and beyond.
"He also played a significant role in the development of the peace process over many years and his contribution, together with others, helped end the conflict and promoted reconciliation.
"His firm belief in dialogue also helped resolve parading issues and, through his membership of the Policing Board he helped shape the accountable policing we have today."