The audit covered the full range of data collection functionality, including data capture, recording and transmission, post transmission data editing, and meter systems development processes.
Nielsen Online uses the NetSight meter in its international panels and its US MegaPanel and is now implementing it into the company's audience measurement products in the US.
Mainak Mazumdar, senior vice-president of measurement science at Nielsen Online, said: "Nielsen Online shares the industry's enthusiasm for quality, transparency and accountability in internet audience measurement, and we are delighted to have completed this important step in the MRC process.
"Our NetSight meter collects -- in real-time -- websites visited, time spent and pages viewed, and is a critical component of delivering accurate audience measurement data and insights to an advertising market that now exceeds $20 billion annually in the US alone."
The MRC will continue with additional audits of other Nielsen Online products, including its SiteCensus and VideoCensus products, as part of the internet audience measurement accreditation process.
George Ivie, executive director of the MRC, said: "I'm pleased that the MRC audit committee now has information regarding Nielsen's NetSight meter and processing systems.
"Nielsen Online is very engaged in the audit process and making important progress, and we are happy with the addition of Nielsen's census/hybrid products to the audit scope."