NHS England has launched a national review into schemes to divert patients away from A&E departments.
According to the Daily Telegraph, the investigation is in response to the death of a 44-year-old man who was turned away from a Bristol A&E department while a pilot scheme to ease pressure was in place, and instead seen by a GP service.
NHS England was unable to say whether its £1 million review had been launched before or after the death of David Birtwistle, who died of a pulmonary embolism in November two days after being diverted from the department.
Following the inquest into his death in March, assistant coroner for Avon Terence Moore wrote to the NHS asking for a national review of "serious incidents and near misses in similar 'front door' services" to take place "as a matter of some urgency".
The decision to send Mr Birtwistle away from A&E meant "further tests, which could have led to an earlier diagnosis of his condition, were not done".
He added: "In my opinion there is a risk that future deaths will occur unless action is taken."
A spokeswoman for NHS England said: "Guidance to hospitals on making sure patients get the level of clinical care they need has been specifically updated in the light of this (the review), so as to make sure that people who need GP care can get it, and people needing specialist assessment can quickly do so.
"GPs successfully look after 300 million patient consultations every year, compared with 23 million A&E visits."
The review is due to report its results in summer 2018, NHS England said.
The Government announced plans for all A&E departments to have a GP-led triage in March's budget, when the Chancellor said £100 million would be made available immediately to make the change.
The British Medical Association has warned that instead of relieving pressure, GPs may encourage patients to visit A&E units.