Lord Justice Haddon-Cave, who is investigating allegations of more than 50 summary killings by UK special forces soldiers as well as claims of a cover-up of illegal activity and inadequate investigations by the Royal Military Police, made the disclosure during a public hearing.
The inquiry has focused on deliberate detention operations (DDOs) at the centre of the allegations. Haddon-Cave stated that the inquiry had identified numerous SAS personnel from whom it wished to hear direct evidence and had issued rule 9 requests – written notices asking for information – to each of them.
"A high proportion have indicated their intention to rely on their privilege against self-incrimination and have refused to answer any questions asked by the inquiry," he said.
The development marks a significant obstacle for the inquiry, which was established to examine whether UK special forces were involved in unlawful killings during operations in Afghanistan and whether subsequent investigations properly addressed those allegations.