The valuable documents were kept under lock and key
After the break-in, all the jewelry was placed under lock and key
The police found the stolen goods under lock and key
He always keeps his passport under lock and key when he travels
The museum ensures all its artifacts are under lock and key
Make sure the safe is under lock and key before you leave
She insisted that her personal diaries remain under lock and key
The secret formula was held under lock and key by the company
The sensitive files were stored under lock and key in the archive
After the incident, the evidence was put under lock and key
Did you put the important documents away?
Yes, they are under lock and key now.
Good, we need them to be safe.
The important papers were secured safely
Those sensitive items were locked away