This is what someone from a local bookstore is claiming based on a book that comes to this conclusion.
The Disciple Whom Jesus Loved - who was that beloved disciple?
The whole book is on line
Who was the disciple that Jesus loved? Trust the Bible evidence.
Conclusion
This Bible study presented evidence in two cases. In the first it was shown that the Apostle John wasn’t “the disciple whom Jesus loved” (the author of the fourth Gospel). In the second facts were cited that indicate this unnamed beloved disciple was Lazarus. Now, let’s review the evidence that's been presented so far.
Pause to pray and ask God to use His Word to lead you to the truth. (This is always a bad sign)
He would have had to write 1,2,3 John as well because of the similarity of all these writings.
Bible study on the beloved disciple, who was the disciple Jesus loved?