No-one was questioned by police and no arrests were made but some material was recovered, police spokesman Dar Maragen said.
"Police searched the office of the Sunday Times and secured some newspapers," said Mr Maragen from Port Louis.
"An investigation has now begun and the Commissioner of Police has started an inquiry into the paper."
Earlier Tanaiste Eamon Gilmore, Ireland's deputy prime minister, would not 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."
Mr Gilmore, who also serves as Foreign Affairs Minister, claimed Mauritian authorities were responsible in ensuring no photographs used as evidence in the murder trial were leaked to the press.
He has ordered Ireland's ambassador to Mauritius, Brendan McMahon, to meet officials on the island, where the 27-year-old was killed 18 months ago.
He said the Irish Government's priority was to make a "strongly driven message of protest" to official authorities over the publication of the images.
The ambassador would also press to know what other steps will be taken in the murder probe after the two hotel workers suspected of the killing were acquitted last week, he added.
"I believe the Mauritian authorities have a responsibility to ensure that evidence did not come into the hands of the media," said Mr Gilmore. "I'm very concerned that did happen."
The McAreavey and Harte families were left devastated yesterday when the Mauritian newspaper published graphic pictures of Mrs McAreavey's dead body at the crime scene, after her murder at the Legends hotel last January.
A spokesman for her widow John and the rest of the family said the publication of the images was repugnant and reprehensible.
Mr Gilmore said he had not seen the photographs, which included a full-length image of Mrs McAreavey's body in her hotel room and close-ups of injuries on her neck.
"I would consider looking at those photos to be an invasion of Michaela's privacy and the privacy of her family," said the Tanaiste.
He said he was shocked by the "disgraceful" publication.
Mr Gilmore said the decision to publish the images was unacceptable and showed a complete lack of respect to the McAreavey and Harte families.
The Tanaiste, who confirmed he had spoken to Mr McAreavey since his return from Mauritius but would not say what they talked about, said it appeared the photographs had been leaked by authorities.
Mr McAreavey and other family members returned home from Mauritius at the weekend, after a gruelling eight-week trial.
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, 27, was the daughter of Tyrone gaelic football manager Mickey Harte.
The teacher was found dead in the bathtub of her deluxe room shortly after lunching with her husband at a poolside restaurant.
Both defendants worked at the hotel at the time.
Elsewhere, a travel agent in Co Donegal has stopped selling trips to Mauritius out of solidarity to Mrs McAreavey's family.
Caroline Davies, who owns Liberty Travel in Letterkenny, said she was disgusted after details emerged during the trial of how authorities treated Mr McAreavey in the aftermath of his wife's death.
"They locked him in a room and told him he would find another wife. I thought that was appalling," said Ms Davies.
"So I took the decision not to sell Mauritius as a mark of solidarity to the family."
The travel shop owner said Mauritius was not a big seller anyway, however it has divided opinion among holidaymakers.
"I've had some people come in since the murder saying 'I hope you're not selling Mauritius', but then others have told me what happened wouldn't put them off going," she said.
Ms Davies added that she would not sell a holiday if it is not somewhere she would be willing to travel to herself.