Avinash Treebhoowoon originally admitted killing Michaela during a police interview, when his counsel was not present.
Chief Inspector Luciano Gerard of the major crime investigation team (MCIT), who led the investion into the killing, was cross-examined for a third day on Friday at the Supreme Court in Port Louis.
He confirmed that Ravi Rutnah, Treebhoowoon's barrister, was not present but insisted he informed the suspect of his right to legal representation.
Treebhoowoon's current defence counsel Sanjeev Teeluckdharry accused the officer of overriding his client's rights.
"You chose to breach the accused's constitutional, fundamental human right to counsel as provided by article 5 of our constitution," he said.
The officer responded: "My lord, before I interviewed him, I informed him of his constitutional rights."
Inspecter Gerard strenuously denies a catalogue of allegations about police brutality relating to claims made by one of the accused.
Treebhoowoon, 31, told police he was involved in the murder of Mrs McAreavey on 12 January last year - two days after she was found dead.
Defence counsel Mr Teeluckdharry claimed lawyers were not allowed a private consultation with the suspect at the time he made the confession.
Treebhoowoon has told the court that police beat him and suffocated him with a towel to get the confession.
Mr Teeluckdharry also challenged the officer to explain why he had seemingly disregarded forensic tests that showed no link to the defendants with the crime scene.
Mr Gerard explained his attitude by highlighting that in his confession Treebhoowoon allegedly claimed that he and Moneea had placed Mrs McAreavey in the bath and then attempted to wash away any traces of their involvement.
The officer was also confronted with claims that his officers threatened to throw Treebhoowoon under a bus if he did not confess.
"My lord this is totally false," he replied.
After the confession statement was signed on 13 January, Treebhoowoon met his father in the police station and was recorded as saying: "Forget about your son now. I have made a mistake."
On Friday, Mr Teeluckdharry insisted that his client said 'Don't forget about your son' and the mistake he was referring to was a decision to move out of the family home weeks earlier after an argument.
The defence counsel for Sandip Moneea also listed a catalogue of errors in the police investigation.
Key witnesses weren't interviewed - these include the occupants of rooms on the same block as John and Michaela and those in the room above.
They also listed a number of items that police failed to find in the room which were discovered after the crime scene was released. These included a red bikini and a multi coloured belt.
The court was also shown a picture of a glass door at room 1025 with five prints on it belonging to neither of the two accused, the victim's husband John McAreavey, nor hotel workers Dassen Narayanen and Raj Theekoy.
Treebhoowoon and his co-accused Sandip Moneea, 42, deny murdering the daughter of Tyrone gaelic football boss Mickey Harte in her hotel room in the island's luxury Legends Hotel.
The prosecution claims the two murdered her when she caught them stealing from her hotel room.
The Co Tyrone teacher's father-in-law Brendan McAreavey and sister-in-law Claire McAreavey were in court to hear the exchanges.
Her widower John remains elsewhere on the island, he will attend court when he is called as a prosecution witness.