STF orders Federal Police probe into paid Polymarket posts promoting Flávio Bolsonaro

The Brazilian Federal Supreme Court Justice Flávio Dino on 27 October 2026 ordered the Federal Police (Polícia Federal, PF) to investigate who paid foreign accounts on X to promote Flávio Bolsonaro by sharing Polymarket election odds. Dino directed police to establish who hired and paid for the posts, where the funds originated, and whether the campaign took part in or knew about the arrangements.

The paid posts and the Polymarket trigger

On 20 September 2026, Polymarket's X account posted that Flávio Bolsonaro had reached an all-time high 58% chance of winning Brazil's presidential election and replied to that post with a link carrying the tracking code “via=x-afr2.” Within about a day, at least five paid-partnership posts on X from foreign accounts — Geiger Capital, Visegrád 24, former US congressman Matt Gaetz, UHN Plus and Eric Daugherty — shared the Polymarket odds without identifying who paid them. The posts were labeled on X as paid partnerships, which signals the author was paid but does not disclose the payer.

Missão (Mission Party), a rival political party, and its presidential candidate Renan Santos filed a complaint at the Superior Electoral Court (Tribunal Superior Eleitoral, TSE) on 23 September 2026 against those five accounts and X Brasil. Missão alleges that the posts, fostered by Polymarket, amount to prohibited foreign funding under Brazil’s electoral law. Polymarket denies that its markets represent support for any candidacy and has not said whether it paid the accounts.

What Justice Dino ordered the PF to investigate

Dino issued the order as ADPF 1178 — an Arguição de Descumprimento de Preceito Fundamental, a claim of breach of a fundamental constitutional principle — giving the matter national-sovereignty status. The order asks the Federal Police to determine:

• who hired and paid the foreign accounts that posted the promoted Polymarket odds;

• the origin of the funds used to pay for those posts; and

• whether the campaign, or any actors in Brazil, knew of or participated in the commercial arrangements.

Dino also directed a separate PF inquiry under Supreme Court supervision into the possible participation of members of the National Congress in the facts under investigation. He described Polymarket as a prediction-market platform prohibited in Brazil and noted regulators had already taken down its Brazil-facing Instagram account in September.

"It is necessary to identify who hired and paid for the posts, where the funds came from, and whether the campaign took part or knew," Justice Flávio Dino wrote in the order.

The broader investigative threads bundled with the order

The paid social posts are one of five lines of inquiry listed in Dino’s order into suspected foreign interference related to Flávio’s campaign. The other four threads ask police to look into:

1. talks between the US group Rockbridge Network and Brazilian businessmen;

2. connections between Rockbridge Network representatives and campaign-associated Tallis Gomes and Pedro San (also reported as Pedro Sang in some documents);

3. any link between campaign funding and Brazil’s rare-earth reserves; and

4. possible algorithm manipulation by technology platforms.

Opening these inquiries does not constitute a finding of wrongdoing.

Allegations, denials and related legal actions

Missão's 23 September complaint led Justice André Mendonça on 25 September 2026 to decline to remove the posts before hearing the parties, while ordering X Brasil to preserve account data and paid-partnership records. Dino quoted Missão’s claim that Polymarket paid the accounts but made no finding on that assertion; the PF must now establish the facts.

Polymarket told Brazilian legal site JOTA in September that its markets "reflect the trades made by their participants," are not electoral polls or official projections and "do not represent support for any candidacy." The platform said it was available to share technical knowledge with authorities as rules for prediction markets are drawn up. Flávio Bolsonaro has denied receiving campaign money from abroad and denies wrongdoing; no public evidence has tied his campaign to arranging the paid posts.

UHN Plus said it would defend "its editorial independence and its journalistic activity." Eduardo Bolsonaro, Flávio's brother, reposted some of the paid items.

Network ties and corporate finance mentioned in the order

Dino's order also canvasses connections involving Rockbridge Network, a US conservative donor group co-founded by JD Vance and Chris Buskirk. Documents cited in coverage name Pedro Sang as CEO of a reported "Rockbridge Network Brasil" and note that Tallis Gomes is a Rockbridge member; both deny brokering campaign funding and Rockbridge says its Brazilian entity never operated.

The order references market and investment ties to Polymarket: 1789 Capital — co-founded by backers associated with Rockbridge — led a $1 billion financing round at a $21bn valuation for Polymarket in August 2026. Founders Fund, linked to Peter Thiel and also connected to Rockbridge, led Polymarket's 2024 Series B round. Donald Trump Jr., a partner at 1789 Capital with ties to Rockbridge Network, joined Polymarket’s advisory board in August 2026. The order does not allege that these financing links relate to the paid social media posts.

Overlapping criminal inquiries and Polymarket markets tied to legal outcomes

Separately, Flávio faces an STF inquiry into alleged money laundering involving his associate the lawyer Willer Tomaz, in which betting activity is central. Documents reported by piauí magazine and a Finance Ministry note obtained by UOL suggested Tomaz was a significant bettor by deposits in 2025; both Tomaz and Flávio deny wrongdoing. Justice Alexandre de Moraes froze up to R$6bn of Tomaz's assets and had ordered Flávio to hand over passports; Flávio missed a mandated 27 October 2026 deadline and his passports were then canceled by police.

Reuters reported on 27 October 2026 that Flávio had left for the United States, citing two sources. Federal Police say there is no formal record of him leaving the country, and Argentina stated he did not enter its territory.

Polymarket also lists contracts tied to Flávio’s legal fate. On 27 October 2026 its market “Flávio Bolsonaro charged or arrested by October 31?” traded between 36% and 47% on about $16,700 in volume. A related contract on whether he returns to Brazil by 31 March 2027 implied 28% at the time of reporting. Polymarket shows other Brazil-related markets with varying volumes; a contract on whether Justice Alexandre de Moraes leaves the court had drawn about $258,000 in volume and sat at 8%.

Polymarket has been X’s official prediction-market partner since June 2025; X’s paid-partnership label marks posts as paid but does not disclose payers. The PF inquiry mandated by Justice Dino will seek to establish the missing payment, funding and knowledge links raised by Missão's complaint and subsequent reporting.Polymarket has been X’s official prediction-market partner since June 2025 and regulators removed its Brazil Instagram account in September.