Publication ethics - rights of a co-author to access full data Institute II is setting up a benchmark project under the lead of main-author MM. 20 other developers participate, run their methods without having access to ground truth data and also MM contributes with his methods results.

A paper is written by MM. Is it the right of one or all of the other 20 developers (results have been submitted to MM already, so there is no reason that tuning/overfitting can happen) that he gets access to GT data to check if the analyses of the results are reasonable? 

The best source for publication ethics known to me is Cope, the Committee on publication Ethics. They have a document for author guidlines (PDF), where it is recommended that an author submits "A declaration that that person takes responsibility for the integrity of the paper". 

This is like always in Ethics only a recommendation, the journal obviously has to do here the final decision. 

In my opinion I can try to get access to the GT by writing MM a mail, nevertheless if not granted, I cannot personally assure the integrity of the paper and have to retract my authorship. Or I get in contact with the editor of the journal if MM is not cooperative and let him decide. 

Am i right about my conclusions? Are there other strong widely followed ethical guidelines about this issue? 

Thanks for further recommondations.
In order for the benchmarking exercise to be convincing to readers, it will ultimately be desirable to release all of the data (and presumably code) so that the comparison can be replicated.  

There's no reason that the ground truth data couldn't be revealed to all participating researchers after they've done their analysis and the results have been frozen but before the submission of the paper.