Shannon gained notoriety last month when she admitted to recording a sexual encounter with The Hills star Heidi Montag.
Vivid's chief Steven Hirsch told TMZ that the new tape features Shannon and her boyfriend, former Smallville actor Sam Jones III.
Hirsch asserted that he received the recording from "a reputable third party" and that he would "love to be able to release it".
Jones responded to Hirsch's comments: "I understand that the guy from Vivid saw footage with Karissa and I in it. We have spoken to our legal team and they will be dealing with this ASAP."
