Officials claim that for every pound spent on running the NAO, £8 is saved via more efficient government practice. It wants this figure to rise to £9 by 2007.
As well as monitoring how efficiently the government is carrying out its policies, it advises on how officials can spend cash more effectively.
Tester said a priority would be to forge better communications with government staff.
'We need frontline workers to understand why their managers are asking them to do things differently in line with NAO recommendations, rather just reach our traditional audience of decision makers,' he explained.
Tester added that his remit included general promotion of the NAO, and persuading select committees to consider NAO reports and recommendations.
He is charged with a team of 24 and reports to his predecessor as comms chief Gabrielle Cohen, who is now assistant auditor general. Cohen previously held the title of director of comms and corporate affairs, but this was changed to reflect the NAO's intention to refocus the postholder's function on PR and marketing.
Tester, who is currently rewriting the NAO's comms strategy, has not ruled out bringing in agency support at a 'later stage'.