Both government and opposition politicians are accused of wrongdoing, and among the files were those which had been with Mahinda Rajapaksa during the last presidential election.
The PM got hold of these files recently.
Accordingly, investigations are to commence against several SLFP members of the present cabinet, who were ministers in the previous administration too.
Wickremesinghe told the cabinet at its last meeting that the accused ministers would be investigated, alleging that some were attempting to sabotage the present government.
He also denounced the baseless allegations by the media against him and the government.
The joint opposition has now decided not to go ahead with its plan to move a no-faith motion against the PM over the Central Bank bond issue.