The European Union has acknowledged it allowed the Chinese government to censor an opinion piece published in the country, removing a reference to the origin of the coronavirus outbreak and its subsequent spread worldwide.

The piece was jointly authored by the EU’s ambassador Nicolas Chapuis along with the ambassadors to China for the EU’s 27 member states to mark 45 years of EU-China diplomatic relations.

In the original piece published on the EU delegation’s website, the ambassadors wrote that “the outbreak of the coronavirus in China, and its subsequent spread to the rest of the world over the past three months” had side-tracked pre-existing diplomatic plans.

But in the version that appears on the website of China Daily, a state-owned newspaper, the reference to the origin of coronavirus in China and its spread is removed.

While the EU Delegation to China said it “strongly regrets” the change, it also admitted that it ultimately agreed for the censored piece to be published because it still contained “key messages on a number of our priority areas.”

“The EU Delegation was informed by the media in question that the publication of the Op-Ed would only be allowed by the Chinese Ministry of Foreign Affairs on the condition that a part of a sentence related to the origins and spread of the coronavirus was removed,” the Delegation said in a statement. “The EU Delegation to China made known its objections to the Chinese Ministry of Foreign Affairs in no uncertain terms.”

“As the Op-Ed states, while the EU and China have differences, notably on human rights, our partnership has become mature enough to allow frank discussions on these issues. This is what makes this incident even more regrettable,” the Delegation’s statement adds.

CNN has asked China’s Ministry of Foreign Affairs for a response.