The Public Protector has found that a tweet about colonialism by Western Cape Premier Helen Zille is in violation of the Constitution.

In a report released on Monday, Public Protector Busisiwe Mkhwebane said that Zille's conduct was tantamount to improper conduct in terms of the Constitution, as well as violating the Executive Ethics Code.

In 2017, Zille tweeted: "For those claiming legacy of colonialism was ONLY negative, think of our independent judiciary, transport infrastructure etc."

"It cannot be said that the Premier's tweet sought to show concern and respect for those who were victims of apartheid and colonialism," said Mkhwebane in an executive summary.

She added that, although Zille had apologised, the apology could be interpreted as a recognition of the negative impact the tweet had on the dignity of a section of the South African population.

The Public Protector said, while the tweet could have been made in the context of Zille's right of freedom to expression, it was still offensive and insensitive to a section of the South African population which regarded it as reopening a lot of pain and suffering to the victims of apartheid and colonialism.

"Section 16 of the Constitution was, therefore, not created to allow anyone, particularly those in positions of influence, to make such statements," said Mkhwebane.

As part of her recommendation on remedial action, Mkhwebane has instructed the speaker of the Western Cape legislature to take appropriate action and hold Zille accountable for her conduct.

Zille's office has issued a statement, in response to Mkhwebane's findings, saying that the premier is likely to take the report on judicial review.

"The premier has already advised the Public Protector that, in her view, such a finding would be unlawful and irrational."

Mkhwebane told reporters that Zille had written to her, saying she had done nothing wrong and was within her rights in terms of freedom of speech when she made the tweet.