LONDON: The British Library has called for a philanthropist to buy Princess Diana’s letters to lover James Hewitt and to donate them to its collection.

Mr Hewitt told CNN’s Larry King on Wednesday that he was prepared to sell the letters but that they would have a multi-million dollar price tag.

Dr Christopher Wright, head of manuscripts at the library, said: “There is no way the British Library would be able to afford some of the sums that have been mentioned so donation would be a preferred route.”

The 63 letters were written between 1989 and 1991 and include ones penned while Mr Hewitt, a former officer in the Life Guards, was serving in the Gulf War.

He told CNN he was interested in selling the letters to a museum or private collector – despite previously saying he would not put them up for sale. He has reportedly been offered $6.4 million for just 10 of the letters from Diana, who was still married to Prince Charles, heir to the British throne at the time of their affair.

Mr Wright said: “It would be satisfactory if they came to rest in a major national institution like the British Library.

“In the case of a major public figure such as the late princess, it is better for their papers to be in a major collection where preservation and access to them is guaranteed. A philanthropic benefactor might consider that buying them and presenting them to the national collection is something they might like to do.”

He added the library would consider “restricting or prohibiting access for a period of reservation to anyone other than heirs” because of the privacy concerns of Diana’s family. The British Library’s collection of royal includes letters from Queen Elizabeth I and Henry VII.

Mr Hewitt told CNN: “I’m not being hypocritical. I’m being honest. I think it’s important to understand that they are or will become important historical documents.”

And he said selling the letters was better than leaving them to sit and “rot in a safe”.

He said: “I think it might be irresponsible not to sell them and to generate something one can do some good with.” When asked if he would use it to “do a lot of good”, he replied he would but did not elaborate.