VATICAN CITY — A Vatican spokesman says authorities are working on recovering a letter written by Michelangelo that was stolen in 1997.

The Rev. Federico Lombardi said the Vatican has recently been offered the return of the letter in exchange for a payment, but that officials have refused. Instead, the spokesman said the matter has been turned over to the Vatican gendarmerie for further investigation.

Lombardi was responding to a report in the Rome daily il Messaggero that said a former employee of a Vatican archive has asked a ransom of $108,000 to return the letter.

According to il Messaggero, the letter is a rare example of Michelangelo’s handwriting, and contains his signature.