Robbers posing as police stormed a house in Chorley, handcuffing a man and taking his 13-year-old daughter.
The terrifying ordeal happened at a home on Railway Road in Brinscall just after 6pm on Monday.
Two men posing as police officers knocked at the door and showed the homeowner a fake ID card and then handcuffed him.
They then took his 13-year-old daughter from the home and put her in a black Ford C-Max which was waiting outside.
They rancacked the house, taking £3600 in cash, as well as three mobile phones, and the house telephone.
The young girl was then returned to the family home after the ordeal unharmed.
Police say it is also possible a black Vauxhall Astra with a number of other men was also waiting outside the home.
They have appealed for anyone who might have witnessed the ordeal, or seen vehicles matching that description in the area, to come forward.
Sgt Andy Bramhall, of Chorley police, said: “It is important people meticulously scrutinise any ID cards which are presented to them, and if they are concerned to contact us.
“We would also appeal for anyone with any information about this incident to come forward.
“Incidents like these are thankfully rare, and we would encourage people with information to contact us on 101 or through the independent charity Crimestoppers anonymously on 0800 555 111. No personal details are taken.”