The entertainer, 75, was interviewed under caution last year by detectives investigating a claim of a sex crime involving a young boy in the 1980s.
He has never been arrested or charged.
His spokesman said the allegations were "completely false" and the star had co-operated fully when he voluntarily met South Yorkshire Police this week.
"Other than restating that the allegations are completely false and that he will continue to co-operate fully with the police, it would not be appropriate for Sir Cliff to say anything further at this time," he said.
Sir Cliff was first interviewed last summer, after a high-profile police raid on his apartment in Berkshire.
Since then, police have confirmed to a parliamentary committee that their investigation has expanded, but said this meant no date could be given for when it would be concluded.
The singer has described the claims he faces as "absurd and untrue".
It is not known what police questioned Sir Cliff about on this occasion.
Singer Sir Cliff Richard has been re-interviewed by police investigating alleged sexual assaults, his spokesman has said.