One of the men accused of murdering Michaela McAreavey was told by police his own wife would be taken from him and given to the honeymooner's widower if he did not confess, his trial in Mauritius was told.
Avinash Treebhoowoon also claims his head was held under water for so long during a brutal interrogation that he started vomiting blood.
But senior Mauritian police officer Luciano Gerard dismissed the allegations as totally unfounded and ridiculous.
The jury at the Supreme Court in Port Louis earlier heard that Mrs McAreavey's husband John was questioned at a police station until past midnight on the day she died last January, before eventually being allowed to return to his hotel.
In another development in the slow-moving case, Treebhoowoon's defence lawyer Ravi Rutnah, who dramatically quit the case yesterday after claiming Chief Inspector Gerard had attacked his reputation, has been permitted to appear as a witness later in the trial.
The pace of proceedings, in particular the cross-examination, also prompted an official statement from the prosecution, urging defence counsel to accelerate their questioning.
During nearly three hours of intensive cross-examination by Treebhoowoon's remaining barrister, Sanjeev Teeluckdharry, Mr Gerard, who led the murder investigation, denied the hotel cleaner was subjected to any ill treatment while in custody.
Treebhoowoon confessed to murdering the daughter of Tyrone Gaelic football boss Mickey Harte in her room in the island's luxury Legends Hotel, but has since insisted the admission was forced out of him.
The 31-year-old and his co-accused, fellow Legends employee Sandip Moneea (aged 42) both deny they murdered the 27-year-old teacher when she caught them stealing from her room.
The tragic honeymooner's father-in-law Brendan McAreavey and sister-in-law Claire McAreavey were in court as the torture claims were addressed.
Her widower is elsewhere on the island, unable to attend court until he gives evidence as a prosecution witness.
Mr Gerard, from the Major Crime Investigation Team (MCIT), faced a barrage of questions about how his officers treated Treebhoowoon in the period after he was arrested at Legends Hotel on January 11 - the day after the murder.
Mr Teeluckdharry accused the officer of making a series of expletive-laden threats against his client as he and fellow officers quizzed him about the murder.
The lawyer said: "My instructions are that you CI Gerard were tired and exasperated and you said the following: 'What did you say? You were beaten? That was not a beating. That was a preview. Now speak'.
"And you ordered your officers: 'Take a van, bring his mother and father and lock them all up'."
The officer vehemently denied the claim.
"That's totally false and ridiculous my lord," he replied.
But Mr Teeluckdharry continued: "You also shouted the following at him: 'This man (John McAreavey) his wife is dead. He will need a woman to live with. That's why we will take away your wife (Reshma), take her passport and send her to Ireland to live with the husband. We will do this because the government is in our hands and no-one can touch us."
Mr Gerard insisted he made no such threat, saying: "Never my lord."
Mr Teeluckdharry said his client then fell at the officer's feet and "implored for pity".
He added: "He then fell on the feet of all other MCIT officers and implored for pity."
The chief inspector replied: "I say again, this is totally false and ridiculous."
Mr Teeluckdharry claimed the accused was beaten around the heels with a PVC pipe and then made to jump up and down so the "blood doesn't clot".
Mr Gerard, unflappable throughout, said the incident never happened.
The lawyer then claimed an officer dunked Treebhoowoon's head repeatedly in a bucket of water in a bid to make him confess.
"That officer plunged his head several times in the water, he was made to suffocate," he said.
"He was made to feel that he's at the mercy of MCIT for a single breath of air."
He added: "My client started to suffocate and started to vomit blood and one officer had some mercy and told them to stop as Avinash Treebhoowoon was suffocating and was vomiting blood.
"And before stopping that ill-treatment, one officer dealt a blow on the back of my client."
The chief inspector again rejected the allegation.
"Never my lord," he said.
Earlier, the lawyer had asked Mr Gerard to confirm whether Mr McAreavey had been questioned at a police station on the day of the murder.
The officer said he was asked questions until around 12.30am when he was escorted back to Legends.
Mr Teeluckdharry asked the officer whether he was aware that travel documents were also taken from Mr McAreavey.
Mr Gerard replied: "It was well afterwards that I became aware that his documents had been taken."
The officer said he did not know why the items had been seized.
The case against Treebhoowoon, from Plaine des Roches, and Moneea, from Petit Raffray, was scheduled to last two weeks but is set to go on for much longer.
Judge Mr Justice Prithviraj Fecknah has already warned a "lengthy trial" is ahead.
As Mr Teeluckdharry concluded his examination for the day, indicating he would require another hour-and-a-half with the witness in the morning, principal state counsel Mehdi Manrakhan said he wished to make a statement.
The state would appeal to counsel for accused number one and accused number two to accelerate cross-examination on witnesses and stick to admissible and relevant evidence," he said.
Counsel for Moneea, Rama Valayden, who had been seated for the day, reacted angrily to the development.
Judge Fecknah said he would return to the issue tomorrow.
At the start of the trial's eighth day, the first without Mr Rutnah present, Mr Manrakhan told the judge that he had no objection to the lawyer being called as an additional defence witness.
Although not in court, the barrister still arrived at the Supreme Court building to work elsewhere inside.
A letter written by Mr Rutnah alleging police brutality by officers investigating the crime which the defence wanted to introduce into proceedings was also not met with a prosecution objection.
Mr Rutnah stepped down after claiming Mr Gerard had attacked his professional integrity while giving evidence.
In a final flourish before leaving court yesterday, the lawyer declared to the jury that he would be back "Arnold Schwarzenegger-style".
He is now set to come good on that pledge later in the trial.
Mr Gerard made a series of claims about Mr Rutnah when giving evidence to the prosecution yesterday.
He said he was late arriving for a meeting with his client, after he signalled his desire to make a confession statement, and also shared food - fried rice - in a convivial atmosphere with investigating police officers.
Mr Rutnah said this amounted to an "accusatory attack" on his reputation that left him with no alternative but to withdraw from the case.