When I was preparing the camera-ready version of a paper, one of my co-author asked me to put in the acknowledgements section that his research was funded by the grant N12345.
Just out of curiosity, I searched the grant number, and found its description: "applying technique X on problem A".
I was very surprised, because my paper is completely unrelated to either X or A. Moreover, I know very well that this co-author has very little background in both X and A, let alone doing research. Although he is a very good researcher, these just are not his expertise.
The grant is for 3 years, and it is going to expire in a couple of months. He has not published any paper related to A or X. However, he has published many papers in completely different topics, e.g. the paper with me, and claimed that they were supported by this grant.
Is it the way to do if your field of research has limited funding? Might he go into troubles if it is discovered by the funding agency that the papers are actually not related to the grant proposal?