I am looking for a prefix to express the meaning of something possibly belonging to a class / category, or being a candidate for the concept in question.
For instance, a "[...]-solution" would be some statement or proposition that could be a solution for a given question, albeit its status of being so or not has still to be established. A "[...]-pathogen" would be a germ whose pathogenic character is still unclear; a "[...]-perpetrator" an alleged perpetrator and so forth. (Actually, I am mostly interested in a more abstract use of the prefix-root-combination).
The prefix should function in the same way as "pseudo-", "quasi-" etc. It would be nice to find something of Greek or Latin origin, but other proposals are fine as well.