The 22-year-old actor was given a photo montage signed by the entire cast after filming his final scenes as Geoff Campbell, but it later vanished after he left it on the show's set.
David Jones-Roberts, who plays Summer Bay's Xavier Austin, eventually had to break the news to Lewis that his present had disappeared.
Lewis told TV Week: "I left it in my pigeonhole and asked David to get it for me the next time he was at work - but someone had nicked it!
"I really would've liked to have had it framed, but I guess someone else is going to keep it or give it to a friend. I'm bummed about that."
Lewis announced that he was leaving Home and Away last year and went on to film forthcoming movie Tomorrow: When The War Began.