MANILA – The International Criminal Court’s (ICC) Office of the Prosecutor has asked Trial Chamber III to keep former President Rodrigo Duterte in detention, arguing that his continued detention is necessary to prevent him from interfering with witnesses.

Acting Prosecutor Mame Mandiaye Niang, in an observation filed on Sept. 14, said there had been no development that would justify changing the chamber’s previous decision to keep Duterte detained.

Instead, Niang said circumstances had changed in ways that heightened the risks associated with Duterte under Article 58(1)(b)(i) and (ii) of the Rome Statute.

“To the contrary,” Niang noted in the filing, “there have been changes in circumstances that have increased the risk Mr. Duterte presents under articles 58(1)(b)(i) and (ii) of the Statute.”

The provisions cited by the prosecutor concern ensuring an accused’s appearance at trial and preventing the person from obstructing or endangering the investigation or court proceedings.

Niang also cited the setting of a definitive trial date, as well as another redacted matter, saying both developments “increase the likelihood of Mr Duterte facing trial and therefore increase the risk that he may abscond.”

The prosecution also said it had added eight incidents to the charges against Duterte since the chamber’s May 22, 2026 decision reviewing his detention.

“The Prosecution has also added ‘eight additional incidents’ to Mr Duterte’s charges since the date of the Decision,” Niang said, referring to the Trial Chamber’s May 22, 2026 decision reviewing Duterte’s detention.

The prosecution based the additional incidents on its still-confidential pre-trial brief.

Niang argued that the increased number of incidents and victims, along with the possibility of a lengthy prison sentence, further supported Duterte’s continued detention.

“The number of incidents and victims, and therefore the prospect of a lengthy prison sentence, have increased, which militates in favour of Mr Duterte’s continued detention.”

Prosecutor cites disclosure of witness names

The prosecutor also raised the disclosure of the prosecution’s witness list to Duterte on Aug. 31.

According to Niang, the list contains the names of prosecution witnesses and details of their expected testimony.

“The question of the risks to witnesses ‘revolves around the possibility, not the inevitability, of a ‘future occurrence’. Mr Duterte’s history shows that he is able and has the means, either directly or through his associates, to interfere with [REDACTED].”

Niang maintained that these circumstances justified keeping Duterte in custody.

“With these submissions, Niang argued, “Mr Duterte’s continued detention is necessary to ensure he does not interfere with witnesses.”

Defense wants fitness ruling first

Duterte’s defense team, however, argued that the detention issue should be considered alongside the pending determination of whether the former president is fit to stand trial.

“The questions of fitness and detention are necessarily linked,” defense counsel Peter Haynes said in an observation published on Sept. 14.

The defense said it had previously told the chamber that it would not submit observations on detention at that point because it expected to revisit the matter after the fitness issue had been resolved.

“Following an order on 15 July 2026 from the Trial Chamber to submit observations pursuant to Rule 118(2),1 the Defence informed the Chamber, parties and participants on 4 September 2024 that ‘it does not intend to submit observations at this time’, but that it anticipated coming back as required after the question of the accused’s fitness to stand trial had been settled,” the filing said.

The defense raised questions about Duterte’s fitness in May and sought a medical examination.

Both the prosecution and defense have since submitted their observations on expert reports concerning his fitness. The prosecution has asked Trial Chamber III to find Duterte fit to stand trial, but the chamber has yet to rule on the matter.

The defense said a finding that Duterte was unfit, followed by an adjournment of proceedings, would be relevant in determining whether there had been a material change in circumstances affecting his detention.

It said it would exercise Duterte’s right under Rule 118(2) to seek a review of his detention after the chamber rules on his fitness, “if the circumstances merit it.”

The submissions come ahead of Trial Chamber III’s latest review of Duterte’s detention, which is expected to be taken up during the third status conference on Sept. 16.

Prosecution, victims oppose bid to revisit charges

Meanwhile, the prosecution and lawyers representing victims of Duterte’s drug war have opposed a separate defense motion seeking to have the charges against the former president refiled.

Duterte’s lawyers asked Trial Chamber III on Aug. 31 to have the charges “properly inform…the accused of the case he needs to meet.”

The defense wants the scope of the charges clarified in terms of the number of counts and seeks an “exhaustive list of underpinning acts” covering the allegations against Duterte.

The former president faces three counts of crimes against humanity of murder. The prosecution alleges that he is criminally responsible for the deaths of 76 individuals in 49 incidents connected to the drug war.

In separate filings dated Sept. 10, the prosecution and the common legal representatives of victims opposed the motion, arguing that the adequacy of the charges had already been resolved by Pre-Trial Chamber I.

“To the contrary, the three counts each have a clear temporal, geographical and material scope, and this is consistent with the requirements of article 74(2) of the [Rome] Statute,” the prosecution said in its 10-page response.

It added, “The…mere disagreement [of the defense] with the analysis of the [PTC] is insufficient to show any defect.”

The common legal representatives of victims asked the trial chamber to reject the defense motion, calling it “procedurally misconceived.”

They argued that the defense cannot reopen the issue by presenting it as a challenge to the “form” of the charges.

“[S]hould the Chamber consider that the defence genuinely seeks to challenge defects in the [document containing the charges], such objections belong to the pre-confirmation stage and cannot now be raised before the trial chamber,” they said in their 10-page response.

The victims’ representatives added that the defense had merely repeated its disagreement with the pre-trial chamber’s earlier ruling and “advance[d] no argument” warranting a reversal.

Trial set for November

Duterte, who remains detained in The Hague, is scheduled to go on trial on Nov. 30, with proceedings expected to continue into next year.

The third status conference on Sept. 16 will cover the prosecution’s witness and evidence lists, the amount of time it needs to present its case and its disclosure of evidence.

The prosecution has also opposed another defense proposal involving the authentication of evidence obtained from open-source and user-generated materials.

It argued that requiring such authentication would be “unnecessary and burdensome” and could delay the trial.

The prosecution said it should be allowed to determine which open-source or user-generated evidence requires expert certification, citing credible sources such as United Nations, nongovernment organization and government websites as examples of material that should not require expert authentication.