The charity commission has been called in to investigate an incident involving the Norwich Puppet Theatre.
The watchdog, which registers and regulates charities across England and Wales, says "concerns" were raised and that the theatre has submitted a "serious incident report" in line with the Charity Commission's guidance.
However, when questioned by this newspaper about what the incident might be, the commission refused to provide further details.
The commission has not yet made any findings, nor has it opened a compliance case or statutory inquiry.
A spokesman for the Charity Commission said: "We are assessing concerns raised with us about Norwich Puppet Theatre Trust Limited to determine what regulatory role there might be for the Commission.
"In line with our guidance, the charity has submitted a serious incident report."
A spokesman for the Norwich Puppet Theatre, who also declined to give more details saying only the incident was "internal", explained the theatre's board had reported it to the commission out of due diligence.
He also confirmed the theatre would not be closing and that it currently has bookings into next year.
The Puppet Theatre came close to closure in 2008 when it faced losing a £60,000 annual grant from Arts Council England.
However, it was saved following the launch of a Norwich Evening News campaign which raised the alarm bells and Norwich Town Close Estate Charity stepped in, among other donors who also contributed.
Almost 50 years of puppet shows
The theatre, which is only one of three building-based puppet theatres in England, has held its residence at St James' Church on Whitefriars since 1980.
After the church's closure in 1972, it was used as a homeless shelter during the mid-1970s before it was chosen to house the DaSilva puppet company and became the Norwich Puppet Theatre.
Ray and Joan DaSilva, whose puppet company was based in Godmanchester in Cambridgeshire, picked Norwich to be the new home for their touring company because of the warm welcome they received during performances at Norwich Theatre Royal.
