The app, Ugly Mugs, allows sex workers to alert each other to potentially dangerous clientsGETTY IMAGES

Irish sex workers have claimed Google could be putting them at risk by blocking key functions on an app used to warn of dangerous clients.

The tech giant decided last year to refine its developer program policies to include limits on call logs and SMS permission access on apps in the Google Play store. The new limitations could have consequences for hundreds of sex workers in Ireland and the UK who use an Android app called Ugly Mugs, which relies on such functionality.

The app, developed by London-based Safe IQ, has been using advanced access features since 2013. It screens incoming calls and text messages to sex workers and alerts them if any number in contact with them is in the app’s database.

It uses…