Highly popular free dating apps owned by Match Group – including Tinder, OkCupid, and Plenty of Fish – do not have clear policies or screening practices to prevent registered sex offenders from signing up.

As a result, people are matching with sex offenders on those apps and, in some cases, have faced attempted sexual assault, according to a new investigation by ProPublica and the Columbia Journalism Investigations.

For the investigation, ProPublica and CJI reporters analyzed more than 150 instances of sexual assault involving dating apps and found that 10% stemmed from dates in which users were matched with people previously accused or convicted of sexual assault.

While Match Group carries out background checks for its paid services, like Match.com, it doesn’t do so for its free apps. A Match Group representative told ProPublica that “there are definitely registered sex offenders on our free products.” A Match Group representative did not immediately respond to Business Insider’s request for comment.

Based in Dallas, Match Group owns 45 online dating brands and reported $1.7 billion in revenue in 2018. Tinder, its largest app, earlier this year became the top-grossing non-game app, according to TechCrunch.

The ProPublica/CJI report identified several registered sex offenders who were able to continue using Match Group dating apps after being convicted.

One Colorado man, Michael Miller, was convicted in 2015 of raping a woman he met through OkCupid. He later created a new OkCupid account and was allowed to keep using the platform for months, according to ProPublica and CJI's investigation. A Pennsylvania man, Seth Mull, had a 17-year history of sex offenses before he started using Plenty of Fish in 2017 - that year, the dating site matched him with a woman who later accused him of rape, according to the investigation.

Read the full ProPublica/CJI report here.