SOME of the British secret service's earliest efforts to tackle Irish republicanism came to light yesterday, with the release of classified documents dating back to the middle of the last century.
The papers show how Britain used dirty tricks, the latest technology and highly paid informants in a bid to undermine Sinn Fein and the IRA between 1853 and the 1920s.
The papers released at the Public Record Office yesterday are among the oldest to be kept from the public, reflecting the continuing sensitivity of the "Irish question" over more than 150 years.
They reveal that informants within the republican movement of the 1860s could earn up to £200 a year from the British secret services - the equivalent of £60,000 today.
But they show that this massive financial inducement was not enough to encourage many republicans to betray their cause, as efforts to infiltrate Sinn Fein after the Easter Rising of 1916 largely failed.
The files detail how speeches by Eamon de Valera were monitored during the First World War for signs of pro German leanings, and how a so called "German plot" was devised to justify the internment of IRA and Sinn Fein leaders in 1918.