The brother of Sinn Fein president Gerry Adams is to take his extradition fight to the Irish Republic's highest court over claims that a letter was being withheld from his legal team.
Liam Adams is wanted in Northern Ireland for the alleged rape and indecent assault of his daughter.
During a brief hearing in Dublin's High Court, Mr Adam's barrister Maeve Corbett said they were appealing to the Republic’s Supreme Court to have the letter between the Crown Prosecution Service in Belfast and authorities in Dublin disclosed to them.
Mr Justice Michael Peart adjourned the case until October 6 this year.
Mr Adams, who handed himself in to Garda last March, has been remanded on continuing bail.
At an earlier hearing Mr Adams' senior counsel Michael O'Higgins said it was necessary they saw the letter because if it suggested any shortcomings in the European Arrest Warrant that echoed their own concerns then it would help their case.
Investigators want to question Mr Adams on 18 charges of sexual abuse, including rape and gross indecency, against his daughter.