The investigation, which will include interviewing current and former Lotto players, is one of the first projects to be handled by the new directorate of performance and communications.
Catherine Forrester, who joined earlier this month as the commission's first performance and comms director said: 'We've monitored sales before but the question hasn't been asked yet, why are Lotto sales in decline?'
She added that the research is likely to start within weeks. A PR campaign to promote the research is set to get underway in Easter when the findings are due.
The restructured directorate will be three-strong.
Forrester, who reports to CEO Mark Harris, added that she wanted to boost stakeholder relations work in the coming months.