New legislation could be passed in Ireland to direct Irish police to appear before the Kingsmill inquest into an IRA massacre, a lawyer said.
A coroner in Northern Ireland is seeking intelligence and other information held by the Garda about the sectarian shooting dead of 10 Protestant workmen by republicans in south Armagh in 1976.
Garda Commissioner Noirin O'Sullivan cannot direct an officer to give evidence to the inquest, which is due to resume next month, without new legislation.
Sean Doran QC said: "The attendance of a garda at legal proceedings outside the jurisdiction would have to be done properly under the auspices of a direction by the Commissioner but the legal authority to give such a direction is absent and that is the reason why legislation is being considered to deal with this particular issue."
Coroner Judge Brian Sherrard said there appeared to be a blockage to a garda witness attending voluntarily.
Legal counsel for relatives of the dead said the attack began with the hijacking of a vehicle and the escape of the gunmen into the Republic and it was only humane that a garda should appear to guide the inquest through the documents.