I'm looking for a suitable word meaning 'according to the source', where which source is obvious from the context. Example sentence
They made foodboxes with meat rather than fish, ostensibly since fish smells when microwaved.
The example is imperfect in the sense that whether fish smells in the microwave is something people might have a personal experience with and so it might feel verifiable by the reader itself, but in the original sentence, there is no way for the reader to verify if true, so I want to convey that I am relaying what the source claims without judgement. I want to do this more succinctly than tacking on '.. according to source' at the end of the sentence.
Ostensibly means roughly 'according to the source' but if I understand it correctly, it also carries an implication that the source is lying or hiding something. I want the meaning of 'according to the source' but without that implication.
Words I've considered:
Apparently. Definition; as far as one knows or can see. This is pretty good but refers more to what I can see than what my source can and says.
Supposedly. Definition; according to what is generally assumed or believed. Nothing is generally believed or assumed in my case, since it's a highly technical statement and not verifiable to the general reader of my text. Supposedly also carries an implication that I am doubting the source which I don't want.
There might be a suitable word I cannot find, or my understanding that ostensibly implies lies might be flawed. Advice welcome regardless of solution. Any ideas?