Gay dating app Grindr has come under fire for sharing information about users’ HIV status or locations with two companies enlisted to optimise its software.

Norwegian nonprofit research group Sintef uncovered Grindr’s data sharing with two companies – Apptimize and Localytics – and concern spread in the US after BuzzFeed reported the findings.

The Los Angeles-based dating company then announced it would stop sharing users’ HIV status with third-party companies, BuzzFeed reported.

Grindr’s chief technology officer, Scott Chen, said sharing data with partners to test and optimise its platform was “industry practice”, but sensitive data was encrypted when sent and vendors were under strict contractual terms to keep it secure and confidential.

“Grindr has never, nor will we ever sell personally identifiable user information – especially information regarding HIV status or last test date – to third parties or advertisers,” Chen said in a Tumblr post.

Chen said “as a company that serves the LGBTQ community, we understand the sensitivities around HIV status disclosure”, but pointed out that Grindr was a “public forum” and “if you choose to include this information in your profile, the information will also become public”.

Grindr users have the option of sharing their HIV status and when they were most recently tested. Researchers expressed concerns that health information combined with other data such as location and email address could result in people being identified.

Online rights champion Electric Frontier Foundation called Grindr’s response “disappointing”.

“You guys should just close up now,” read one of the comments in an online chat forum under Grindr’s Tumblr post.

“No one cares about your efforts or industry standards. You betrayed the LGBT community in more than just the one way.”