Detectives investigating a blaze at Southwater, Horsham, in which a camper van was destroyed and a nearby annexe was damaged have appealed for witnesses.
They would like anyone who saw anything suspicious or who may have other relevant information to come forward.
The alarm was raised at 3am on Sunday 23 December. The camper van was parked on a driveway at Foxfield Cottages close to its junction with Andrews Road. No one was hurt.
Subsequent examination suggested the fire was started deliberately and police are keen to speak to anyone with knowledge of the incident.
They are asked to contact Sussex Police online or by calling 101, quoting serial 46 of 23/12.
Alternatively they can visit Crimestoppers or contact the independent charity anonymously on 0800 555 111.