The Church of England has confirmed it is investigating a "non-recent" safeguarding matter reported in the Diocese of Lincoln.
The Church's lead bishop on safeguarding, the Rt Revd Peter Hancock, described it as "a very serious matter".
The Church said: "All appropriate information has been passed to police.
"Until their processes have been completed nothing further can be said publicly."
Bishop Hancock said: "It will be a matter initially for the diocese, although there is oversight now from a national safeguarding team."
Lincolnshire Police said it was aware of a safeguarding allegation reported in the diocese.
However, a spokesperson said the alleged incident did not occur in the force's area and the matter had been passed to the appropriate force.