OSTERLEY House could double as Wayne Manor for the new Batman film, according to rumours circulating online.
In a rare move, the listed building will be closed to the public for four days next month, June 15-17 and June 22, for 'private hire'. Some rooms within the house will also be closed between now and July 3.
The closures have been shrouded in secrecy, sparking rumours The Dark Knight Rises, starring Christian Bale as the caped crusader, is being filmed there.
A spokeswoman for the National Trust, which manages the 18th-century house, refused to confirm or deny the rumours. She would not even say whether filming of any sort was taking place there.
A statement on the National Trust website says: "The decision to close the house is always a difficult one but it provides a crucial opportunity for us to generate some much-needed funds, which will enable us to undertake some vital house conservation works."
The Dark Knight Rises is scheduled for release next July. The star-studded cast also includes Anne Hathaway, as Catwoman, along with Gary Oldman and Morgan Freeman.
Anyone visiting Osterley House between now and July 3 is advised to check www.nationaltrust.org.uk or call 020 8232 5050 first for details of closures.