THE arrest of former royal butler Paul Burrell has reopened the extraordinary rift between Prince Charles and the Spencer family.

It has emerged St James's Palace attempted to prevent the investigation into the alleged thefts from the estate of the late Princess of Wales.

Last night palace officials said there was 'deep concern' among the Royals that this could mean Prince William and Prince Harry being summoned to give evidence exposing them to an unnecessary public reprise of their mother's life. But Diana's sister, Lady Sarah McCorquodale, with the backing of her brother Earl Spencer, pressed for the case to go ahead.

The Mail on Sunday can reveal that during the ten-month police investigation, the palace considered a meeting between Burrell, 38, and Charles who would say that he considered Burrell innocent but it would be better to return all the items.

Meanwhile Earl Spencer rebuffed palace approaches to help get the case dropped in the interests of both the boys and Diana's memory.

And Lady Sarah continued to help police by identifying items and supplying names of other potential witnesses.

This enabled Scotland Yard to expand their inquiry, even sailing on the QE2 incognito to watch Burrell lecture tourists on life with Diana.

Last night a source said: 'Lady Sarah and her brother were determined to do the right thing by Diana. If it clipped the wings of St James's Palace then well and good.

'While Earl Spencer has taken a back seat, he is behind his sister 100 per cent.' Lady Sarah is also said to resent Burrell's profile as protector of Diana's memory.

She did nothing to prevent his sacking from his [pound]38,000a-year job with the Princess Diana Memorial Fund on which they worked together.

The relationship between her family and St James's Palace has always been frosty.

Earl Spencer's speech at Diana's funeral was seen as a sideswipe at Charles and earlier this year he attacked the Prince for not visiting the Princess's grave at the family home at Althorp Park.