Google has confirmed that it is trialling videos that automatically start playing when they appear in its search results.
The test comes at a time when its rival Apple is preparing to make it easier to prevent videos from self-starting within its web browser.
Facebook has also faced criticism for recently automatically turning on sound for auto-play videos on its platform.
One expert said the feature could be a fresh money-spinner for Google.
But for now the firm is unwilling to reveal its intentions.
"We are constantly experimenting with ways to improve the search experience for our users, but have no plans to announce at this time," a spokesman said.
The BBC understands, however, that Google will reveal more about its plans on Thursday.
Google's auto-play feature was first reported by industry site The SEM Post earlier in the week.
The videos appear on the right-hand side of results and appear to be limited to queries involving films at this time. Only a limited number of users are affected.
In the examples that SEM Post saw, the viewer still had to turn on the sound if they wanted to hear it and the feature was restricted to desktop searches.
The news site was able to see the feature on the international, UK and Canadian versions of Google's Search service. However, when tested by the BBC, the videos appeared but did not auto-play.
The clips were sourced from YouTube. At this time they do not feature pre-roll adverts, which are included when the same trailers are viewed directly on the video-streaming site.
Even if Google opts not to pursue an ad-based model, it could still profit from the feature if it charges film studios and other industries to pay for the privilege of having their clips start without prompting.
"Auto-play videos are deeply annoying to a vast swathe of users, so if Google decides to go down this route it will no doubt enrage a very vocal part of the internet community," commented Ben Wood from the CCS Insight tech consultancy.
"However, there is always a commercial angle to any of these decisions and there are clearly some significant benefits to being able to auto-serve content even if people don't necessarily want it."
The inclusion of auto-play video adverts in Facebook, Twitter and Instagram has already proved to be a revenue-spinner for the three platforms.
"I think that we proved that having a quick start auto-play can be a good experience," said Facebook's chief Mark Zuckerberg in 2013 after adding the feature.
"If it's good content then that can be really good."
However, Apple revealed last month that it had felt compelled to make it easy for users to block the technology in the next version of its MacOS operating system.
"Sometimes you go to read an article and instead of finding something to read you get... video that auto-plays and disrupts your whole reading vibe," said software engineering chief Craig Federighi at Apple's developer conference.
"Safari detects the sites that shouldn't be playing video and puts you in control - you can always push play."
It is as yet unclear whether Apple's blocking facility would apply to Google.