Twelve pictures of the crime scene, including graphic images showing the injuries inflicted on the 27-year-old, were including in this week's edition of the Sunday Times, a Mauritian tabloid.
The McAreaveys' lawyer in Mauritius, Dick Ng Sui Wa, described the publication as "outrageous" and said legal action was being taken.
"The matter has been reported to police - to the Commissioner of Police himself - this morning," he told UTV.
"I have just received information that the police are going to act upon that and will probably do the needful to seize the photographs, and also to seize any materials which are offensive to public morality."
The First and deputy First Ministers have condemned the actions of the newspaper.
"There can be no justification for the publication of these images, which in no way could be deemed to be in the public interest," DUP leader Peter Robinson said.
"Have the McAreavey and Harte families not already suffered enough?
"This paper by their actions has inflicted more pain and suffering on them and the decision to print these images is utterly contemptible."
Sinn Féin's Martin McGuinness added that he intends to travel to London later this week to discuss the situation with the Mauritian High Commissioner.
"To date justice has been denied to the McAreavey and Harte families and the publication of these photographs, at the end of what has been a very difficult week for them, has compounded their grief," he said.
"We are dismayed and astonished at this blatant invasion of privacy."
Meanwhile, the Irish Tánaiste also lent his voice to the condemnation on Monday, when he said the Mauritian authorities should have ensured that the photographs did not get into the hands of the media.
"I believe the Mauritian authorities have a responsibility to ensure that evidence did not come into the hands of the media. I'm very concerned that did happen," said Eamon Gilmore.
I cannot accept that printing of these photographs of Michaela could in any circumstance be considered acceptable and it shows a total lack of respect at both her memory and the feelings of her family who have already suffered so much.
Tánaiste Eamon Gilmore
The Minister for Foreign Affairs has ordered Ireland's ambassador to Mauritius to meet officials on the island, where Mrs McAreavey was killed 18 months ago.
In a statement, a spokesman for the McAreavey and Harte families described the publication of the pictures as "reprehensible and repugnant".
"As the families struggle to come to terms with the result from the trial, this reprehensible and repugnant action by this newspaper is not only insensitive to their grief but it marks another low in the treatment of John, the two families and the dignity of Michaela," the statement, which was released on Sunday, read.
Mr Gilmore said he had not seen the photographs, and he felt that looking at those photos would be "an invasion of Michaela's privacy and the privacy of her family."
The Labour politician also refused to rule out the possibility of sending Irish detectives to undertake their own investigation into the murder - like French authorities did following the murder of Sophie Toscan du Plantier in Co Cork in 1996.
"That is something we may have to look at down the line," he added.
"But the immediate issue that arises today arises firstly from the publication of the photographs. We have to take immediate action to deal with that."
Taoiseach Enda Kenny also condemned the newspaper, which has no connection to any British or Irish company.
Mr McAreavey and other family members returned home from Mauritius at the weekend, after a gruelling eight-week trial.
The Tánaiste confirmed he had spoken to Mr McAreavey since his return from Mauritius but would not say what they talked about.
Legends hotel workers Sandip Moneea and Avinash Treebhoowoon were cleared of Mrs McAreavey's killing by a jury at the Supreme Court in Port Louis last Thursday.
Mrs McAreavey, the only daughter of Tyrone Gaelic football manager Mickey Harte, was found dead in the bathtub of her deluxe room at the Legends resort in January last year, shortly after lunching with her husband at a poolside restaurant.
Both defendants worked at the hotel at the time.