A Household Cavalry soldier and his wife have appeared in court charged with raping a schoolgirl under 13.
Trooper Simon Davies, 37, and his wife Fiona Parsons-Davies, 44, were accused of a string of paedophile offences as detectives investigated a suspected online child pornography ring, sources said.
Davies, who is understood to have served in Afghanistan, is based at Windsor's Combermere Barracks, where Prince William and Prince Harry both served.
The husband and wife appeared in custody at Reading Magistrates' Court earlier this week over offences alleged to have occurred in January.
Davies is charged with three counts of rape of a child under 13 years, while Parsons-Davies is accused of rape, aiding and abetting rape and child neglect.
They were both remanded in custody to appear at Reading Crown Court on December 15.
Police have searched several addresses including the couple's home on Broom Farm estate, two miles from Windsor Castle.
The Household Cavalry consists of the Life Guards and the Blues and Royals.
The Household Cavalry Regiment - which Davies serves with - has an operational role in armoured fighting vehicles on the front line, while the mounted regiment is equipped with horses, carrying out ceremonial duties on state and royal occasions.
A Ministry of Defence spokesman said: "The matter is subject to a civil police investigation and it would therefore be inappropriate to comment further whilst this is ongoing."