An inquiry into Hope House School in Newark has been opened by the Charity Commission following an anonymous complaint.
The independent special school on Barnby Road caters for children and young people aged five to 19 who have an autism spectrum disorder. It had its first full-time pupil in 2010 and currently has 25 pupils on roll.
Concerns were raised about the school's governance and administration and a books and record inspection was carried out that raised a number of regulatory issues.
The Charity Commission has launched a statutory inquiry as a result.
It will focus on:
*Whether the trustees have exercised enough oversight and control of the charity;
*If the financial controls of the charity are adequate and its money properly spent solely in furtherance of its charitable objectives;
Potential conflicts of interest;
*Whether connected party transactions have been properly managed;
*If there has been any unauthorised trustee benefit.
The commission says it has exercised temporary powers to restrict the charity's transactions to ensure any money spent is only in the interests of the charity's objectives and is being closely monitored.
A statement from the commission says an inquiry is not a finding of wrong-doing but will examine issues in detail and decide if action needs to be taken.
Mr Matt Evans, a director at Hope House, said the directors at the school were working with the Charity Commission to refute the anonymous allegations.
"Whilst doing this our amazing staff and supporters continue to enrich the lives of the wonderful children at Hope House School," he said.