The phrase "a controversial aspect of" is correct and usable in written English.
It can be used when discussing a topic or issue that has differing opinions or debates surrounding it.
Example: "One controversial aspect of climate change policy is the debate over carbon taxes."
Alternatives: "a contentious point regarding" or "a disputed element of".
This regulation must be applicable across national borders, as the subject of BP's nationality has proven to be a controversial aspect of the fall-out from the oil spill.
A controversial aspect of carotid artery stenting (CAS) is the placement of a stent with or without predilation.
A controversial aspect of this work is that the modification may be a delete instead of an insert, which may be counterproductive for the user.
A controversial aspect of the US policy is that drone attacks are carried out not by the military but by the Central Intelligence Agency.
A discovery by a Harvard researcher may shed light on a controversial aspect of the life of Jesus Christ.
A controversial aspect of the war was the trials and hanging of Chief Leschi, deemed responsible for killing during the conflict.
A sometimes controversial aspect of cap-and-trade systems is the ability to 'offset' emissions or invest in projects outside the cap-and-trade program that reduce, rather than do so directly.
The volume and hence mass assigned to hind limb segments is also an equally controversial aspect of non-avian dinosaur biology (see below).
The ontology of species is a problematic and controversial aspect of medieval theories of perception and cannot be analyzed here.
For one, it expanded the Medicaid program, a critical and highly controversial aspect of the law, by adding up to a $19 billion in benefits in January.
Attracting inward investment has always been an important, and often controversial, aspect of local government.
