Germany's smartphone app to trace coronavirus infections is ready to be launched this week, Health Minister Jens Spahn said, according to Reuters.

After delays to ensure the bluetooth technology would work at the correct distance, the government says the app will be a vital tool to help avoid a second wave of infections.

“It's coming this week,” Spahn told ARD television, but he declined to confirm German media reports that the app would be launched on Tuesday.

The app uses bluetooth short-range radio to detect and contact people at risk of infection by coronavirus and does not rely on a centralised database.