Apple is stepping up efforts to develop its own search technology as US antitrust authorities threaten multibillion-dollar payments that Google makes to secure prime placement of its engine on the iPhone.

In a little-noticed change to the latest version of the iPhone operating system, iOS 14, Apple has begun to show its own search results and link directly to websites when users type queries from its home screen.

That web search capability marks an important advance in Apple’s in-house development and could form the foundation of a fuller attack on Google, according to several people in the industry.