Ivor Bell, 79, faces two counts of soliciting Jean McConville’s killing in 1972.
The defendant was due to plead at a scheduled arraignment hearing in Belfast Crown Court ahead of his trial. But the hearing was adjourned after Bell’s barrister told the judge a medical examination was to be commissioned.
Granting the four-week adjournment, Judge Seamus Treacy said: “This relates to unfitness to plead issues.”
White-haired, moustachioed Bell, from Ramoan Gardens in West Belfast, sat in the dock during the brief legal exchanges. His lawyers made it clear the pensioner denies the offences at previous hearings.
A number of Mrs McConville’s children watched on from the public gallery.
The mother, aged 37, was dragged from her home in Belfast’s Divis flats complex by an IRA gang of up to 12 men and women. She was accused of passing information to the British army — an allegation later discredited by the Northern Ireland Police Ombudsman.
Mrs McConville was shot in the back of the head and secretly buried 50 miles from her home, becoming one of the “disappeared” victims of the Troubles.
It was not until 1999 that the IRA admitted the murder when information was passed to gardaí in the Republic.
Her remains were found on Shelling Hill beach, Co Louth, by a member of the public in August 2003.
No one has been convicted of her murder.
The case against Bell is based on the content of tapes police secured from an oral history archive collated by Boston College in the US, which saw academics interview former paramilitaries
It is alleged one of the interviews was given by Bell — a claim he denies.