He thanked the families for their “unwavering patience and co-operation”.
Their support had been “invaluable” as officers gathered information “in the hope of seeking the answers they want and deserve”.
ACC McLoughlin said the force remained “committed to keeping those families affected at the heart of this investigation”.
A 46-year-old man was arrested on 9 March last year on suspicion of prevention of a lawful and decent burial, fraud by false representation and fraud by abuse of position.
A 54-year-old woman was arrested in July on suspicion of money laundering offences.
Both remain on conditional police bail, the force confirmed.
Emma Hardy, the MP for Hull West and Haltemprice, thanked officers for “their meticulous work”.
“It’s been a long wait for progress for those affected by these horrific crimes, so I’m sure this news will provide relief,” she said.
“I want to pay tribute to those who have been affected. You have shown us all the true meaning of resilience and community in the most difficult circumstance.”
Julie Butcher, senior operations manager at Victim Support, said the charity was continuing to support those affected, including via a dedicated phone line, on 08082811136.
