Ownership of environmental samples (or other material) analyzed during a PhD I am a PhD student researching environmental science in Europe. As such, I have received hundreds of environmental samples, including water, sediment etc. over the past year and a half, the extensive work with which has let to two peer-reviewed publications. However, I am still struggling to understand who actually owns these samples - is it the faculty, my supervisor, myself, or the party that sent the sub-samples in the first place? My question is basically - what can I do with the samples without looking at potentially serious issues. More specifically:

1) If there is considerable disagreement between myself and my supervisor as to which analyses are to be carried out on said samples, from a strictly legal standpoint, am I free to carry out the analyses I want to, and which I am sure will benefit my thesis, even though my supervisor disagrees with my approach. There is more than enough material to carry out both mine and my supervisor's methodology.

2) Can I sub-sample and share some of these samples with other institutions or individuals for the purposes of possible (not documented or otherwise agreed upon) collaboration? Again, I strongly suspect my supervisor will not be happy with this, but would it be considered illegal or as academic/other misconduct. Obviously, my supervisor would know and probably be a co-author on any ensuing publications (if any).

What are the possible repercussions of the above? Could I be expelled from the program, or my PhD revoked after the fact? I could not find any discussion on such topics, and instead kept coming across the usual "fabrication, falsification and plagiarism"-related discussions, hence my questions!
Since you ask for legality, you need to consult a lawyer for an answer. Everything expressed here is my personal opinion based on my experience as a researcher. It is not legal advise.

You say, you received the sample based on a collaboration of your university with the sample supplier. This probably means, you acted as a representative of the university when receiving them, because you wouldn't have received the samples if you were not affiliated to the university. From this it follows that the university owns the samples. This is also reinforced by the samples being processed with university resources.

I wouldn't do anything with these samples against the university's or my supervisor's wishes. 

However, if you have disagreements about this with your supervisor, you should try to solve this conflict or even find someone who can mediate the dispute. A compromise that makes both of you happy might be achievable.