under lock and key

Participants would need to be kept under lock and key so their food intake could be tightly managed.

They still use equipment the Yankees donated in 2019 during MLB’s debut in Europe — baseball’s are in sparse supply in the U.K., so the Mets keep their gameday stockpile under lock and key.

These lines from the award-winning movie “Spotlight” told the story of how the Catholic Church systematically sexually abused children and kept these crimes under lock and key.

But in contrast to the rival port of Southampton on the south coast, Portsmouth's actual "family silver" is staying under lock and key, certainly not for sale.

For now, however, even the almighty Wade isn’t capable of ginning up some bogus charge by which to keep the San-Ti cult leader Ye Wenjie under lock and key.