The Labour Party is not in possession of any personal information about individuals which contravenes the Data Protection Act, according to the Data Protection Commissioner.
The decision was taken following a complaint made by Nationalist general secretary Paul Borg Olivier.
The Commissioner, John Ebejer, said he first wrote to former PL general secretary Jason Micallef in March 2009 for his reaction to the PN claims.
A technical inspection of the PL's data processing system was held in April.
Mr Ebejer said it had been established that no personal or sensitive data on individuals was being kept by the Labour Party that breached the terms of the act.