The cases of Saudi stand-up comedian Fahad al-Butairi and his wife, Loujain al-Hathloul, a women's right-to-drive activist, who were arrested in 2018, has resurfaced following a Twitter thread detailing their disappearance.

In a series of tweets, American writer and television producer Kirk Rudell spoke about his friendship with the Saudi couple who tried to challenge the kingdom's strict social rules.

The tweets about their disappearance went viral, spotlighting Saudi Arabia's crackdown on activists and the killing of journalist Jamal Khashoggi in the Saudi consulate in Istanbul in October last year.

I'd like to see what they could do in this world, if they were given the chance.



I'd like the government of my country to not take payoffs to look the other way at human rights atrocities.



I'd like to have that dinner with them some day. — Kirk Rudell (@krudell) January 2, 2019

Rudell tweeted about messages he shared with the couple after meeting them in Los Angeles a few years ago.

"I'd like to see what they could do in this world, if they were given the chance," said Rudell, adding, "I'd like to have that dinner with them some day."

In a follow-up tweet, Rudell said he was "overwhelmed" by the response to his tweets, including one from California Congressman Adam Schiff, who said he would contact Saudi Arabia's ambassador to the United States about the case.

"I've been overwhelmed by the interest in and support of this story. It has been humanity-affirming and the best possible expression of Twitter in action. My intention was to bring the plight of Fahad and Loujain to the attention of people who can do more for them than tweet," he wrote.

Both Butairi, 33, and Hathloul, 29, were arrested in 2018. Butairi's whereabouts are unknown, while Halthloul remains incarcerated.

Hathloul was among a group of more than a dozen Saudi women's right-to-drive activists detained and allegedly tortured by electrocution, flogging, and sexual harassment, according to Human Rights Watch and Amnesty International.

For years, she advocated for women's right to drive in the kingdom and, in 2013, actively participated in a campaign where she posted videos of herself driving in an attempt to encourage women to do the same.

With an active social media presence, the 29-year-old had been arrested several times for defying the now-lifted ban on women driving in Saudi Arabia.

Most of the arrested activists campaigned for the right to drive and an end to the kingdom's male guardianship system, which requires women to obtain the consent of a male relative for major decisions.