Lord Gifford QC, for Hill, accused the three officers of failing to record visits made to Hill by Sir Peter Imbert, who was later to become Metropolitan Police Commissioner, and another detective.
He made it clear there was no implication of Sir Peter, then a detective superintendent, being party to any concealment.
However, he said, the three Surrey policemen had told lies and their evidence was thus seriously discredited.
Hill, 39, was released from custody when he and the other members of the Guildford Four had their convictions for bombing pubs in England quashed.
He is now appealing against another conviction, for the murder of a former soldier, Brian Shaw, in Belfast in 1974.
On the second day of the appeal, Hill, neatly dressed and with shoulder-length hair, was again accompanied in court by a number of members of the Kennedy clan, including his wife Courtney and her mother Ethel, widow of Robert Kennedy.
Hill admits signing a statement confessing to the murder of Shaw, but says he did so after intense ill- treatment in Guildford police station. Surrey police witnesses said he had not been abused or even visited by detectives during that period.
Lord Gifford said it had now emerged detectives had met Hill twice during the disputed period and this was evidence which had not been made available to the trial judge.
It was clear, he said, that instructions had gone out that the visits should not be recorded.
If all that happened during the 24 hours was perfectly innocent, then there would be no object in concealing the visits. But if, as Hill had all along claimed, there were other longer and improper visits, then one could see a clear motive for the police witnesses being told to suppress any record of those events.
The hearing, which is expected to last up to three weeks, is being attended by a large number of observers from international human rights organisations, as well as half a dozen members of the Kennedy family.
The first witnesses are to be called on Monday.
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