After authorities discovered 35 remains at a location on Hessle Road in Hull in March, along with what seemed to be human ashes, Legacy Independent Funeral Directors has been the subject of an investigation.
As part of the inquiry, a 54-year-old lady was detained on suspicion of money laundering on Wednesday.
In March, a 46-year-old man and a 23-year-old woman were taken into custody on charges of fraud by false representation, fraud by abuse of position, and preventing a proper and decent burial.
The man, who was out on bail, was reportedly also taken into custody by Humberside Police on suspicion of stealing and producing or supplying materials for fraudulent activities.
As part of the investigation, three Legacy Independent Funeral Directors locations in Hull and the East Riding of Yorkshire were raided.
Hundreds of families have been left wondering if they have the ashes of their loved ones since investigators revealed the probe; some have even said that they have been informed they most surely have the wrong remains.