Rosberg was travelling at 320kph when he suffered a tyre failure, pitching him into a spin.
'The tyre tests in Barhain regarded a number of prototypes, which were completely innovative in terms of structure and compounds, with the aim of developing the most suitable solutions for the next season,' said Pirelli, following the conclusion of the three day test.
'This morning Nico Rosberg’s Mercedes was fitted with one of these prototypes, a tyre which had only been tested in the laboratory and which will not be proposed again.'
'Thus, the safety of the tyres which will be supplied for the next Championship is not in question.'
'The accident which happened to Rosberg’s car is being investigated and the findings will be communicated to the FIA and the teams.'
Mercedes was one of four teams competing in the test, along with Red Bull, Ferrari and Toro Rosso.