An arson attack wrecked a garage on London Road, Lynn, during the early hours of Thursday, police say.
The incident happened at around 2.30am and officers are keen to hear from anyone who saw any suspicious activity in the area at around that time.
A Norfolk Police spokesman said the blaze badly damaged a double garage which stands close to the junction with South Everard Street and John Street.
Anyone with information about the incident is asked to contact PC Gary Morris via the non-emergency 101 number.
Witnesses can also contact Crimestoppers free and anonymously on 0800 555111.