Police give update on 'poison plot' at Blackpool Victoria Hospital but key questions remain unanswered

But the force again declined to answer several key questions about the probe, including whether any bodies have been exhumed, how many confirmed victims there are, and what the nine-month-old investigation is now focusing on.

It also declined to say how many funerals have been cancelled or postponed, or how many families have been contacted by detectives.

The lack of update comes two months after local MPs said it was “vital” the public is kept informed and called on police to be more open.

Seven medics arrested on suspicion of poisoning patients continue to be ‘released under investigation’, a spokesman for Lancashire Police said.

No arrests have been made in connection with the spin-off investigation into the alleged murder of Valerie Kneale, 75, the force added, though it would not say what injuries the resort grandmother suffered.

“There’s no update here,” a spokesman said. “The investigation is ongoing and enquiries continuing.”

The first medic to be arrested, a nurse, was held on Friday, November 9 last year, the day after the hospital called in police following revelations by a whistleblower.

Another two medics were arrested in December, with a further four held in April. All have been suspended from hospital duty.

Det Ch Insp Jill Johnston said at the time: “I understand further arrests could be concerning but I would like to reassure people we have a dedicated team of detectives working on this investigation. Given the number of arrests and the nature of the allegations, it remains a complex and sensitive inquiry. No timescales have been set I would ask people to remain patient.”

Detectives believe elderly patients were given prescription-only drugs to keep them heavily sedated at night.Up to eight possible victims were understood to have been identified by December, it was previously reported.

The same month, a grieving daughter, who did not want to be named, was told to cancel her dad’s funeral so tests could be done on his body.“They rang me to say my dad was having a post-mortem and he would be taken away,” she told The Gazette.

“We were told to cancel the funeral because it was all being investigated.”

During a post-mortem examination on Mrs Kneale, who died on the stroke unit on November 16, “suspicious” but unspecified injuries were found, leading to a separate investigation.

Blackpool South MP Gordon Marsden said in June: “There will inevitably be some concerns that they don’t feel able at this point – as their investigation continues – to be more transparent.”

And Fylde MP Mark Menzies added: “Given the number of people treated on this ward and in the wider hospital, it is vital we have updates from police on this investigation.”

Blackpool North and Cleveleys MP Paul Maynard said: “I recognise the need to keep the public informed on such an important matter while, at the same time, not compromising the ongoing investigation.”