The phrase "a controversial example" is correct and usable in written English.
It can be used when referring to an instance or case that is subject to public disagreement or debate.
Example: "The study presented a controversial example of how social media influences political opinions."
Alternatives: "a contentious case" or "a disputed instance".
In a controversial example involving unconventional gas wells in a sandstone formation near Pavillion, Wyoming, EPA detected contamination in shallow monitoring wells from 2010 to 2011 [88].
(Sisi, a former general, is a controversial example to cite -- activists and scholars say his oppressive rule in Egypt may actually be radicalizing the country's youth, and his actions in neighboring Libya have helped prolong the security vacuum there that ISIS has exploited).
A more controversial example is a woman suffering from domestic violence, where Fahy said doctors or medical professionals would know or suspect there was a problem but not tell the police or other agencies.
A very controversial example was reported in The Daily Star: a student died jumping from a building after learning that he had failed in the S.S.C. examination, but when the script was re-examined it was found that he had passed with comfortably and an error had apparently been made by the head examiner in assessing the script (The Daily Star 2016).
A particularly controversial example of incapacitation is the so-called "chemical castration" of sex offenders with hormonal drugs that supposedly reduce or eliminate the sex drive.
Davies took a less than charitable view of how happiness-led government initiatives have played out in real-world settings, citing the introduction of cognitive behavioural therapists to some job centres as a particularly controversial example.
For a less controversial example, we can look at the way revolutionary Marxism destroyed Students for a Democratic Society in the 1960s, with ambitious upstarts marginalising and then expelling senior members by accusing them of willingness to accommodate bourgeois capitalist imperialism.
A more controversial example is language.
Rusnock (2000) proposed a less controversial example: the idea "1" has both smaller content and smaller extension than the idea "solution of the equation x2 = 1".
Carpenter the reformed gentleman lived with his working-class lover, George Merrill, in an early and controversial example of an openly gay relationship.
An interesting case to discuss in this section of a commercially successful, but controversial, example of a compound produced from an Actinobacteria isolated from another well-known Chilean environment is that of rapamycin (also known as sirolimus), isolated by Brazilian researchers from a strain of Streptomyces hygroscopicus endemic of Eastern Island, or Rapa Nui [ 40].
