Correction at 1400 KST: A previous version of this article stated that Virgil Griffith had been released on bail last month, when it fact he was released this Thursday.

A U.S. grand jury this week formally indicted an American blockchain researcher for a controversial April 2019 lecture at a cryptocurrency conference in North Korea, court papers revealed Thursday.

The 36-year-old Virgil Griffith stands accused of conspiracy to violate the U.S.’s International Emergency Economic Powers Act (IEEPA), as well as illegally providing services to the government of the DPRK and violating U.S. sanctions against the country.

He could face up to 20 years in jail if found guilty.

The Singapore-based hacker — once described by the New York Times as a “Man of Mystery” — was arrested in November, seven months after traveling to the DPRK and giving a lecture at the “Pyongyang Blockchain and Cryptocurrency Conference” despite a U.S. travel ban prohibiting American citizens from visiting the country.

“Virgil Griffith provided highly technical information to North Korea, knowing that this information could be used to help North Korea launder money and evade sanctions,” U.S. Attorney Geoffrey S. Berman said at the time of his arrest.

“In allegedly doing so, Griffith jeopardized the sanctions that both Congress and the president have enacted to place maximum pressure on North Korea’s dangerous regime.”

That lecture, the U.S. government said at the time, had been “pre-approved” by North Korean authorities, and saw him share information on how the country might use blockchain technology to evade sanctions.

Griffith was, according to the U.S. government, asked by one of the conference’s organizers to specifically emphasize the “potential money laundering and sanction evasion applications.”

Court documents released this week stated that one of his alleged accomplices is expected to be arrested soon.

Notably among the organizers of the April conference were members of the pro-DPRK Korean Friendship Association (KFA), a representative of which during promotions for that event last year had said that U.S. citizens “will be approved” should they want to participate — an approval Griffith did not obtain before traveling to North Korea.

But Griffith appears to have been unaware of the risks involved in skirting tough U.S. laws on North Korea, even going so far as to share a photo of his DPRK visa on social media.

His case has prompted a wave of debate within the cryptocurrency community, with some of his colleagues protesting his arrest and defending the “Blockchain and Peace” lecture on the grounds of free speech.

Much of his case will, however, hinge on whether prosecutors can prove that Griffith was engaged in a broader effort to help North Korea evade international sanctions.

“My sense, and I should reiterate that I am not a lawyer, is that arguing that the lecture itself is problematic will be harder than focusing on the conspiracy to enable cryptocurrency financial transactions,” Will Scott, a computer scientist and former lecturer at the Pyongyang University of Science and Technology (PUST), told NK News.

“If the lecture does become a point of contention, the two arguments I would expect from defense would first to be to call into question whether there was anything not already publicly available online that was conveyed in the lecture, and second an appeal to the first amendment freedom of speech,” he added.

Griffith was released on a $1 million bail on Thursday.

Edited by James Fretwell