In 1989, two Northern Irish policemen were shot dead in south Armagh in an IRA ambush. A tribunal was set up in 2005 to investigate the deaths. The Irish government may well now regret having set it up. The investigation has touched a raw nerve in the country's past. Irish police are suspected of collusion in their murders, and allegations have surfaced that British military intelligence were also aware of a plot. The British government has shown reluctance to aid the investigation, and one key witness was even prevented from giving evidence by the defense ministry.