Prince Harry will reportedly lose the title of His Royal Highness following an administrative error.
The Duke of Sussex has become embroiled in ongoing tensions with the Royal Family amid claims attempts were made to ostracise Meghan Markle.
It is understood discussions were had as to whether the couple should have their titles removed as they left the the 'Firm'.
It now appears he will lose his HRH title at an exhibition for his mum Princess Diana, reports Birmingham Live.
Dresses worn by the Princess of Wales went on public display at Kensington Palace last week, with the placard "Lent by HRH the Duke of Cambridge and HRH the Duke of Sussex".
Notices for the dress display will now be changed to reflect Harry's new status, The Sunday Times reports.
Harry, 36, and William, 38, donated two of their mother's dresses to the Royal Style in the Making show.
A spokesman for the Royal Collection Trust said the dresses were "loaned by HRH the Duke of Cambridge and the Duke of Sussex".
They added "due to an administrative error, for which the Royal Collection Trust was responsible, the labels were incorrect and will be updated".
The two dresses on show are Diana's famous ivory taffeta and lace wedding gown, designed by David and Elizabeth Emanuel.
She wore the stunning dress to marry Charles at St Paul's Cathedral in 1981.
The second dress donated by the dukes is their mother's wedding day going-away outfit, a peach skirt suit by Bellville Sassoon.
The exhibition, which runs until January 2, also looks at designers who dressed the Queen, Princess Margaret and the Queen Mother.
