Didcot Power Station collapse: Manslaughter investigation
The men died when the boiler house came down in February 2016.
A pre-inquest review hearing at Oxford Coroner’s Court heard an update on Thames Valley Police’s investigation.
The force said it was looking at charges of corporate manslaughter, gross negligence manslaughter, and serious health and safety breaches.
Det Ch Insp Craig Kirby told coroner Darren Salter an evidence file was passed to the Crown Prosecution Service on 29 December.
He added: “A number of individuals and companies suspected of committing offences have been identified and interviewed under caution.”
He said so far officers had carried out 1,921 witness interviews and there was not yet an expected completion date for the investigation.
Mr Salter said the case had been “extraordinarily difficult” for the families of the dead workers.
He added that whether a full “substantive” inquest takes place would depend on the outcome of the joint police and Health and Safety Executive investigation.
Workers Ken Cresswell, 57, John Shaw, 61, both from Rotherham, Michael Collings, 53, from Teesside, and Christopher Huxtable, 34, from Swansea, died in the collapse.
It took more than six months for their bodies to be recovered from the site.
The coal-fired station was shut in March 2013 after 43 years of operations.
The original plan was to have the site cleared by the end of 2017.