They were first detained in Romania in December 2022, then released from house arrest in August 2023.
According to a statement from DIICOT earlier in the day, four houses were searched on Wednesday morning in the capital, Bucharest, and in Ilfov county.
The brothers were then driven to DIICOT in Bucharest for questioning - and afterwards taken into custody in handcuffs and under armed guard.
They have been remanded in custody for 24 hours.
According to the brothers' lawyer, they are being kept until prosecutors can ask a judge either to detain them for longer, move to house arrest or release them.
Asked by the BBC what he had to say the new allegations, Andrew Tate shouted over his shoulder that the prosecutors were "desperate".
"Wait 'til you see," he said. "They say I have lover-boyed the mother of my children. We tricked them into having kids.
“Ask them this time what the evidence [is]."
He described the file as being "more pathetic than the first".
Earlier on Wednesday, the brothers were met by a small crowd of reporters and supporters as they arrived at the DIICOT building in police vans.
As Andrew Tate entered the building he greeted a local blogger who asked why he was back at DIICOT. Grinning, Tate replied that he "didn’t know", before shouting through the closing door that he was in his "favourite place".
Two police officers, who both had their faces covered by balaclavas, were seen carrying heavy sacks into the same building - presumably with items taken during a search of the brothers’ home and other properties.
Asked to comment on the latest developments, their lawyer - Eugen Vidineac - said the latest allegations were not yet clear, as he hadn’t yet seen the file.
He said he didn’t yet know “what we’re dealing with”.
Officers at DIICOT have 24 hours to question the brothers. After that, if they want to remand them in custody, they would have to bring them before a judge.
The lawyer said he did not expect the brothers to be detained because their movements are already restricted as they await trial for other charges, including forming and organised crime group and human trafficking.
In an apparent response to the raid, Andrew Tate posted on X (formerly Twitter): "The Matrix is real. And they have a tried and true playbook.
"Slander is their number one tool and the process is the punishment. But unfortunately for them, Good always wins in the end."
Andrew Tate is a self-described misogynist and was previously banned from social media platforms for expressing misogynistic views.
He has repeatedly claimed Romanian prosecutors have no evidence against him and there is a conspiracy to silence him.
The Tate brothers, former kickboxers who are dual UK-US nationals, are accused of exploiting women via an adult content , which prosecutors allege operated as a criminal group.
Two female Romanian associates were also named alongside the brothers in an indictment published in June last year, and seven alleged victims were identified.
The internet personalities are also wanted in the UK in connection with separate and unrelated sexual offences allegedly committed there.
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