No new cases of the Clostridium difficile (C.diff) bug have been identified at a city hospital at the centre of an infection investigation.

NHS Lothian previously revealed that two patients at Edinburgh Royal Infirmary (ERI) who contracted the bug had died of underlying health conditions.

A further 12 cases of the bug - described by health chiefs as a "cluster" - were also being investigated at the same hospital in the city's Little France area.

Since news of the 14 cases emerged yesterday, no more have been identified and tests are being carried out to see if any of the cases are linked.

Health chiefs do not expect the results to come through until next month.

Since the cluster was identified in early November, four patients have recovered and been discharged home, NHS Lothian said.

The eight patients who remain in hospital are being cared for in isolation.

Two of the patients who tested positive for the infection are described as being "very unwell", but the severity of their conditions is not said to be due to C.diff.

Infection prevention and control procedures have been "reinforced" at the hospital and the five affected wards remain open.

Melanie Johnson, executive nurse director at NHS Lothian, said: "Investigations are ongoing to establish if there is a link between the cases, but we always act as if cases are linked and implement action to prevent cross transmission.

"Our robust surveillance procedures meant that we were able to identify these cases quickly and take the appropriate action."

Affected patients in the wards and their families have been told about the infection, the health board said.

Last month, an inquiry into the deadly Vale of Leven C.diff outbreak found the bug was a factor in the deaths of 34 out of 143 patients who had tested positive for the infection at the hospital in 2007 and 2008.

Scottish statistics show that levels of the C.diff bug among hospital patients have, however, fallen in recent years.