Irish police have apologised to the PSNI for questioning journalists in NI about the murder of a former Sinn Fein official without informing them. Gardai said people interviewed had not been connected with the crime, but were spoken to in case they had information which could help detectives. They said the failure to inform the PSNI in advance was an oversight. A PSNI spokesman, accepting the apology, said co-operation between the two police forces remained high. " Like this Accidently crossing over Borders without permission has never happened before between both Forces."