Under what circumstances can the university council withhold Ph.D. degree? This a case 28 years ago where the defense committee approved the dissertation and recommended granting the degree. The department council and the college council both approved granting the Doctoral degree to the candidate. However, the university council did not approve awarding the degree and did not give formal reasons to the lower councils. 


  What are the norms in north American universities? Under what circumstances can the university council withhold (or deny granting the Doctoral degree) Ph.D. degree to a candidate?


I am not allowed to disclose the university name. The university is in the Middle East.
The system you / they are operating under with multiple approvals needed is not normal in North America. The normal case is that the committee makes the decision, and there is no further consideration. Someone can lodge a complaint which may lead to an investigation by the relevant university-level governing body ("The Graduate School"), which could lead to overturning a committee approval, if it was found that there was something seriously wrong. The final "decision" is usually made by an even higher body, often called "The Trustees", but that is normally pro forma -- except, again, if there is something seriously wrong with the case. Of course there may be North American universities that are more than two sd's from the norm.

By "seriously wrong", I mean that there was proof of academic misconduct, or possibly a wanton abandonment of academic standards by the committee.