A fraud inquiry surrounding Stuart Porter Antiques in Stamford involves several hundred thousand pounds worth of antiques, police believe.
Officers investigating the business have arrested three men aged 54, 30 and 33 and a 19-year-old woman in connection with the investigation in the Stamford area, along with a 58-year-old man and 51-year-old woman in the Cleveland area.
All six have been released on police bail.
Officers believe the fraud involves the theft of several hundred thousand pounds worth of antiques.
Several properties around Stamford and in other parts of the country have been searched and a significant amount of antiques have been recovered.
Officers have appealed for anyone who thinks they may be a victim in relation to this matter to get in touch with DI Peter Grayson by calling 101 and quoting incident number 273 of August 30.