There was widespread condemnation across the political spectrum as politicians united to condemn the video
In June, a video emerged on social media that appeared to show a group of people mocking the murder of Ms McAreavey that created outrage.
There was widespread condemnation across the political spectrum as politicians united to condemn the video, while the Orange Order said an inquiry had begun into what they referred to as "utterly abhorrent".
Mrs McAreavey (27) was strangled in her room at the Legends Hotel in Mauritius on 10 January, 2011.
The teacher, who had married husband John ten days earlier, was attacked after she returned to her room alone and disturbed a burglary.
The man, who was arrested on Wednesday, has since been released on bail pending further inquiries.
Three men previously attended for interviews on a voluntary basis.
In June we reported how investigating the sectarian video that mocked the murder of Michaela had been working to establish if a crime had been committed.
“Our investigation into this incident is ongoing. On June 5, we interviewed one male, who attended voluntarily for an interview,” a PSNI spokesperson said at the time.
A file will be prepared for review by the Public Prosecution Service “in due course”, the force said.
Investigators are trying to establish if a crime was committed by posting the video online, under electronic communications legislation.
A person is guilty of an offence if he or she “by means of public communications network a message or other matter that is grossly offensive”.
The video that sparked anger showed a group of men believed to be attending a Northern Ireland centenary celebration — laughing, clapping, cheering and banging tables strewn with beer cans, as others sing an offensive song about the 27-year-old who was murdered while on her honeymoon in Mauritius in 2011.
Mrs McAreavey’s father, GAA manager Mickey Harte, did not speak about the incident.
However, widower John McAreavey posted on Twitter: “Michaela was a vessel of love, courage and dignity. Hate can hurt, but never win.”