Officers investigating Legacy Independent Funeral Directors in Hull have recovered 35 bodies and a “quantity of what we suspect to be human ashes”, Humberside Police said.
Two people arrested in connection with the investigation, which was sparked by reports of “concern for care of the deceased”, have been bailed, the force said on Tuesday.
A 46-year-old man and a 23-year-old woman were held on suspicion of prevention of a lawful and decent burial, fraud by false representation and fraud by abuse of position.
They have both been released on bail.
Chief constable Thom McLoughlin told a press conference: "So far, we are pursuing extensive lines of inquiry, and have special search and forensic teams conducting thorough searches of various business premises that are linked to the suspects that were detained this weekend.
"I can confirm that a man and a woman have been arrested on suspicion of prevention of a lawful, decent burial, fraud by false representation and fraud by abuse of position.
"They have since been released on police bail with conditions whilst our investigation is continuing.
"I recognise that this is a distressing time for all of those affected and I have no doubt it will have a significant impact across all our local communities and beyond."
Mr McLoughlin said the force has recieved more than 1,000 phone calls from the public over Legacy Independent Funeral Directors since Friday.
The police raided three funeral businesses in East Yorkshire in response to a “concern for the care of the deceased” last Wednesday.
They were seen cordoning off three branches of Legacy Independent Funeral Directors in Hull and the East Riding area as officers investigated on site.
DCS Gawthorpe said a direct telephone line has been established to help victims and encouraged anyone who is worried or has information to get in contact.
At the time, Detective Chief Superintendent Simon Gawthorpe said: “At the core of this investigation will potentially be heartbroken and devastated families and loved ones and we want to provide them with the consideration and support they need and are fully entitled to.”