1 of 3 | Deer rest near the Royal Lodge, the former official country residence of Britain's former Prince Andrew and his family, in Windsor, Britain, on Oct. 29. File Photo by Tolga Akmen/EPA

June 5 (UPI) -- Andrew Mountbatten-Windsor, formerly Prince Andrew, was taking in undisclosed rental income by subletting cottages on royal property, the National Audit Office reported Friday.

Mountbatten-Windsor sublet three cottages on the Royal Lodge estate while the king paid rent for royal palaces for him and his daughters. The report by the National Audit Office, a public spending oversight organization, is the first on royal residences in 20 years.

Mountbatten-Windsor did not pay rent at the Royal Lodge because he paid $10 million, or about $8.67 million, for repairs in 2005. He also paid about $1.35 million when he took over the least in 2003.

The report said Mountbatten-Windsor was allowed to sublet property at the Royal Lodge due to a provision in the lease. Other royal properties allow sublets to generate income with the permission of the Crown Estate.