The evidence used to convict Lucy Letby of poisoning babies is flawed, seven leading experts have said, in a dossier that will be submitted to the miscarriage of justice watchdog.

The former nurse’s legal team will on Thursday hand an 86-page report to the Criminal Cases Review Commission (CCRC) which they say casts “serious doubt” on her convictions.

Letby, 35, was found guilty of deliberately poisoning two baby boys with insulin on the neonatal unit at the Countess of Chester hospital in August 2015 and April 2016 respectively.

The prosecution told jurors at Letby’s trial there could be “no doubt that these were poisonings” and that “these were no accidents” based on the babies’ blood sugar results.

A detailed analysis of the cases due to be handed to the CCRC on Thursday suggests jurors were “misled” about several aspects of the insulin cases, Letby’s legal team said.

The report by seven experts claims that the Roche immunoassay test used in the two cases – and presented as proof of deliberate insulin poisoning – is unreliable.