An inquest into the deaths of two IRA men killed by an undercover Army unit should examine whether detectives treated soldiers charitably, a lawyer said.
Daniel Doherty, 23, and William Fleming, 19, were killed in the grounds of Gransha Hospital in Derry in December 1984.
It was alleged the pair, both from the city, planned to attack an off-duty member of the Ulster Defence Regiment (UDR) when soldiers ambushed them, firing almost 60 shots. It is understood the SAS and the Army's 14th Intelligence Company were involved.
A lawyer for the dead men's families told a preliminary inquest hearing in Belfast more evidence should be forthcoming.
Karen Quinlivan QC said: "Ultimately what this is about is establishing whether there was a culture in place which facilitated collusion. I cannot imagine an RUC officer would admit that they are very charitable towards a soldier."
She recalled evidence from a previous inquest into the SAS killing of IRA men Martin McCaughey and Dessie Grew near Loughgall, Co Armagh, in 1990. She said it emerged that a member of the Ministry of Defence said the RUC was willing to "tip the wink" for soldiers going into interviews.
Ms Quinlivan said: "We feel any evidence of that culture of the RUC treating soldiers differently than they would treat someone else in lethal force...all we are asking is that evidence is taken from the relevant witnesses."
Peter Coll, representing the MoD, said she was making a very serious point.
"If any of the officers identified were to be specifically asked whether in fact in this case there was a tipping of the wink in relation to the soldiers during the Fleming investigation they would be duty-bound to answer the question truthfully."
An inquest was held two years after the shootings but in 2010 Northern Ireland attorney general John Larkin QC ordered another hearing after finding that police documents had been withheld from the coroner at the time.
The MoD is set to resist moves to identify the Army unit responsible.
Ms Quinlivan has said it was important that the name be made public during the inquest, particularly given the context of an alleged security force shoot-to-kill policy that operated at the time.
At a previous hearing Mr Coll said if the coroner supported disclosure of the name the MoD would likely apply for it to be withheld on national security grounds.