Contacting a reference for verification as an editor I am an assistant editor of a local health journal and recently an author submitted a paper on the psychometric property of a translated instrument.

I have requested for a proof of acknowledgement of the original developer allowing the translation, in which the authors were not able to find, citing the time lapse. Would it be fine if I email the owner myself and ask if this was true?

Thank you all.
I think that since the authors are making a claim that will eventually be public if the paper is published, you can do this certainly. 

If you have any suspicions of misconduct then due diligence might also require that you verify the accuracy of the translation, but that is a different issue.