A cheap and widely available steroid has been found to reduce mortality in the sickest Covid-19 patients.

Hydrocortisone, an anti-inflammatory drug, could save one in every 12 patients and will be recommended for use in NHS coronavirus patients.

It is the second drug found to be effective in reducing mortality in those with severe symptoms of Covid-19.

Researchers from Imperial College London and the Intensive Care National Audit & Research Centre found that patients receiving intensive care who were treated with hydrocortisone for seven days had a 93% chance of a better recovery compared to patients who were not treated with the steroid.

The benefits of hydrocortisone were announced alongside analysis from seven trials involving three different types of steroids - including dexamethasone, which has already been found to reduce mortality and is widely used.

The studies found that treatment with one of dexamethasone, hydrocortisone or methylprednisolone led to an estimated 20% reduction in the risk of death.

Professor Anthony Gordon, who led the research into hydrocortisone, said: "The studies published today show that we now have more than one choice of treatment for those who need it most.

"Steroids are not a cure, but they help improve outcomes. Having a choice of different types of steroids, all of which seem to improve patient recovery, is great as it helps ease the problem of drug supply issues."

A total of 403 patients of various ethnicities were recruited from across the world for the hydrocortisone study, including patients from 88 hospitals in the UK.

Researchers say there is no benefit for choosing to treat a patient with either dexamethasone or hydrocortisone over the other, but it offers more options for cheap and effective and treatments and gives clinicians more choice on what to use.

There were too few patients involved in tests of methylprednisolone to enable researchers to estimate its impact with assurance.

The steroids do not work for those with milder symptoms, but the evidence strongly suggests that they reduce the lung inflammation in patients with COVID-19 who are seriously ill and require oxygen support for their breathing difficulties, regardless of age or sex.

NHS chief executive Sir Simon Stevens said: "One of the distinctive benefits of having our NHS is that we've been able to mobilise quickly and at scale to help researchers test and develop proven coronavirus treatments.

"Just as we did with dexamethasone, the NHS will now take immediate action to ensure that patients who could benefit from treatment with hydrocortisone do so, adding a further weapon in the armoury in the worldwide fight against COVID-19."

Professor Martin Landray, one of the chief investigators of the Oxford University-based RECOVERY trial, which looked at dexamethasone, said: "The results are clear: Among critically ill patients with Covid-19, low-dose corticosteroids such as dexamethasone significantly reduce the risk of death.

"Since the emergence of Covid-19, the search has been on for treatments that can improve survival. Corticosteroids are inexpensive and widely available.

"This additional evidence of their efficacy is therefore particularly welcome as the treatments can be used to save lives worldwide."