John 1

John the Baptist was very clear when -

"...the Jews sent priests and Levites from Jerusalem to ask him, Who art thou?
20 And he confessed, and denied not; but confessed, I am not the Christ.
21 And they asked him, What then? Art thou Elias? And he saith, I am not. Art thou that prophet? And he answered, No.
22 Then said they unto him, Who art thou? that we may give an answer to them that sent us. What sayest thou of thyself?
23 He said, I am the voice of one crying in the wilderness, Make straight the way of the Lord, as said the prophet Esaias."  (John 1:19–23)

John denied that he was Elijah (and Elias), the Prophet that would restore priesthood keys, but he was the Elias prophesied that was to come to prepare the way for the Savior.