6-oxo is a supplement/steroid (touted as an effective aromatase inhibitor) which has been around for some time. It's been covered before.
No, nothing like the M-1P products I had mentioned before.
As far as whether it could cause a positive, that would be something I would discuss with the manufacturer.
If whomever the testing agency may be, is using RIA, as pointed out in the link, it could very well cause a false positive.
Hope that helps.