BANGKOK — The former president of the American Chamber of Commerce in Myanmar has been detained upon his return to Yangon after the organization said it was looking into suspicious financial transactions by ex-board members.

Adam Castillo, a founder and owner of the security risk management firm AGS Myanmar, was detained Thursday at Yangon International Airport, according to an associate who spoke on condition of anonymity, citing safety concerns.

Castillo’s company told The Associated Press it was an “ongoing matter” and refused to comment further. Castillo did not respond to an email sent through his personal website.

The U.S. State Department said it was aware of reports that an American had been detained in Myanmar but could not comment further “due to privacy considerations.”

Myanmar’s military-backed government hasn’t released any official statement. The government, the Yangon regional government office and the Yangon Regional Police Department did not answer requests for comment. Authorities in Myanmar, in the midst of civil war, rarely speak to international media.

But several outlets close to the military, including NP News, reported that Castillo had been arrested after the American Chamber of Commerce filed a complaint against him. He was president of the organization from 2023-2025.

Asked about the complaint, the chamber’s executive director, Myat Phyu The, said she could not give details but said the organization’s May 29 annual report “covers the issue at hand.” The organization promotes American businesses.

The report says the current board last year uncovered suspect transactions “undertaken by former board representatives” and referred the matter to a law firm for review.

Investigators discovered that “a former board representative” had signed a contract in November 2024 with a Washington-based public relations firm, which paid him $300,000 that was “apparently collected and disbursed outside AMCHAM Myanmar’s accounts.”

“The signature exceeded the signing limits of individual board representatives, the board never approved the agreement,” the report reads. “AMCHAM Myanmar received no funds, made no payments, and received no services, and the matter was not disclosed to the statutory auditors.”

The report mentions that “two former members of the board” were involved in the case but does not identify either by name or say what legal action was taken by the organization. Myat Phyu The would not elaborate.

A June 12 statement on the organization’s website said the board “has taken appropriate steps to safeguard the interests of the organization and its members.”

Myanmar has been wracked by violence since the military ousted democratically elected Aung San Suu Kyi in 2021 and brutally suppressed the nonviolent protests that followed. That triggered armed resistance by pro-democracy guerrillas and ethnic minority militias seeking to oust the military rulers.

Since the military’s takeover, Myanmar has seen a rise in reported detentions of foreigners, particularly foreign journalists covering the political crisis.

Founded in 2013, AGS Myanmar says on its website that in addition to security, it also provides services including commercial cleaning and pest control.

Castillo’s company biography says he is a former U.S. Marine officer who served in Afghanista, and current chair of “Republican Overseas Myanmar,” which it says was established in 2024 to promote “America First policies in Myanmar and across the region.”

It was not immediately clear where Castillo had traveled before returning to Myanmar and being detained. However, posts on his Instagram account show that a day before his arrest he attended a business forum in Kuala Lumpur, Malaysia, where he also promoted a recently released book.

Castillo’s memoir, “Finding Our Voice,” recounts his experiences in Myanmar amid political turmoil, violence and economic collapse following the army takeover, according to its synopsis.

It was not clear whether the book played any role in his detention.