David de Carvalho, the chief executive of the NSW Education Standards Authority, condemned the treatment of Ellen van Neerven who was subjected to abusive comments and messages from students who had sat the English exam.

"I am appalled by the abuse of the author," Mr de Carvalho told Fairfax Media. "This is a completely inappropriate response and I hope those involved see fit to apologise to Ms van Neerven."

The controversy was sparked after students sitting the HSC English exam on Monday were asked to analyse Ms van Neerven's poem Mango - one of three unseen texts included in section 1 of English Paper 1.

Students were asked to "explain how the poet conveys the delight of discovery".

The exam question and poem was the subject of lively debate on Facebook and HSC discussion groups, but some students directed vulgar and abusive comments at Ms van Neerven.

"In all honesty there wasn't much to analyse cos (sic) it reads like a 4 year wrote it," wrote one student.

Another post compared the author, whose first book, Heat and Light won a number of prizes including a NSW Premiers' Literary Award, to a monkey at a typewriter.

Mr de Carvalho's intervention came as students defended a message on social media comparing Ms van Neerven to a monkey as not racist, but "an extremely unfortunate coincidence".

Students also expressed concern about retribution from exam markers following messages posted on social media from a person claiming to be an assessor.

A NESA spokeswoman declined to comment on the threats of retribution against students: "NESA is unable to disclose the identity of HSC markers due to privacy reasons.

"The exam papers do not identify individual students or their schools".

More than 5500 HSC markers will assess exams across NSW. NESA publicly advertises for HSC markers each year.

She said the integrity of the HSC English exam had not been impacted by the controversy.