According to a newly released report, the country arrested nearly "2.82 million violators of residency, work and border security systems" in the last two years.
The exact numbers of detainments round up to "2,827,564 offenders, including 2,204,460 for violating residency regulations, 432,461 for labor violations and 190,643 for border violations."
Saudi authorities imposed immediate penalties against 424,223 of the arrested offenders, and transferred 385,618 others to "their respective diplomatic missions to obtain travel documents." Around 719,801 of those arrested have since been deported.
The latest statistics also revealed that "47,863 people were arrested while trying to cross the border into the kingdom, 50 percent of whom were Yemeni citizens, 47 percent were Ethiopians and 3 percent were of other nationalities."
Saudi citizens who were involved in transporting or helping violators were also detained by authorities.
The report stated that nearly 3,533 nationals were arrested under the sweeping campaign.
The kingdom has zero tolerance towards illegal expats
In 2017, the kingdom launched a campaign called "A Nation Without Violators," granting illegal workers a three-month amnesty period to sort out their paperwork and leave the country. The period was later extended by one month.
At the time of its launch, Major General Mansour al-Turki, security spokesman of the Ministry of Interior, spoke of the campaign during a press conference, saying:
"The campaign is aimed at all expatriates who do not hold valid iqamas (residency permits) or identification papers in the kingdom and have the residency or labor regulation or both, or those who have entered the Kingdom on Hajj or Umrah visa or transit and have not taken the initiative to depart after the expiry of their visas."
Those who don't leave during the grace period are arrested by authorities.
Weeks after the campaign launched, officials announced a 50,000 riyal ($13,332) reward to anyone who reports illegal expats to authorities.
The reward was announced during a meeting headed by Jamaan Bin Ahmad Al Ghamidi, the kingdom's consultant to public security. In a statement he made at the time, Al Ghamidi warned of a zero tolerance policy towards anyone who employs or hosts illegal expats.
He also explained that anyone who violates the labor laws of the country would be strictly reprimanded, and went on to say that "illegal expats present security, economic, social and health threats to society."