London ? The British Library has made a public plea for a benefactor to help it acquire the intimate letters written by Princess Diana to her one-time lover James Hewitt.

The library said Friday that it would respect the privacy concerns of Diana’s family by considering prohibiting access to the correspondence to anyone other than her heirs for an unspecified period.

Hewitt recently said he was keen to sell the 64 letters handwritten by the princess during their affair. Media reports have suggested the former army officer was seeking a price running into several millions of dollars.

Christopher Wright, the head of manuscripts at the British Library, said the letters would be a historically valuable addition to the institution’s collection of royal and aristocratic correspondence.

Royal letters already under lock and key at the library date back to the 16th century and include correspondence from Henry VII, Catherine of Aragon and an epistle from Queen Elizabeth I to the Earl of Essex.

“Once papers like these have entered a public collection such as the British Library, both their physical safety and public access to them is guaranteed,” Wright said.

He warned that the letters could disappear or be damaged in the hands of a private collector.

“That would be a loss for scholars from around the world,” Wright said, adding that the library would need a donor to help it acquire the letters.

The affair between Hewitt and Diana began when he gave her riding lessons.

After Hewitt cooperated in a 1994 book about their affair, called “Princess in Love,” Diana acknowledged the relationship and said he had let her down. The princess died in a car crash in Paris in 1997.