Police are appealing after a white Ford Transit van the family had rented was stolen while parked outside a home on Lightridge Road in Huddersfield on June 1.
The van is a Luton model and was bearing the registration MV12 0HL. The suspect or suspects are believed to have taken the van between 11.30am and noon when a second van was being filled.
Thousands of pounds worth of possessions were in the van when it was taken. Items in the van included: a Mama's and Papa's grey wardrobe, white wardrobe and chest of drawers; a Batman lamp, baby's cot, children's Star Wars toys and children's soft toys; Oakley's snowboarding googles, jackets, trousers and fleeces; several items of jewellery, including a sentimental snake bracelet; kitchenware, white goods, pots and pans
PC Joanne Coldwell, of Huddersfield Neighbourhood Policing Team, said: "Our enquiries remain ongoing. I would ask members of the public to cast their minds back to June 1 and ask for anyone who has any information or witnessed any suspicious activity in the area, to get in touch with police.
"The victims lost a large number of possessions in this theft and we would appeal for anyone who is offered any of the items described or sees them for sale, to please get in touch with police."
Anyone with information is asked to contact Huddersfield police on 101, quoting crime reference 13170248013.