NET
18 Now the Jewish religious leaders refused to believe that he had really been blind and had gained his sight until at last they summoned the parents of the man who had become able to see.
Darby
18 The Jews therefore did not believe concerning him that he was blind and had received sight, until they had called the parents of him that had received sight.
KJV
18 But the Jews did not believe concerning him, that he had been blind, and received his sight, until they called the parents of him that had received his sight.