London, England (CNN) -- Britain's Prince Andrew has denied knowing anything about his ex-wife Sarah Ferguson's alleged offer to an undercover tabloid newspaper reporter to sell access to Queen Elizabeth's second son for £500,000 ($723,000).
His comments came after News of the World posted a video on its Web site Sunday that appears to show Ferguson accepting money from an undercover reporter in exchange for an introduction to Prince Andrew.
Ferguson is also filmed on hidden camera telling the reporter -- who was posing as a wealthy businessman -- that a payment of £500,000 "opens doors" to Andrew.
She then shakes hands with the reporter after he accepts the deal.
On Monday the royal family moved quickly to distance itself from Ferguson, who has never been far from the headlines since she married Prince Andrew, the Duke of York, in 1986. The couple separated in 1992 and divorced four years later.
"The Duke of York categorically denies any knowledge of any meeting or conversation between the Duchess of York and the News of the World journalist," Buckingham Palace said.
Prince Andrew has carried out his role as a British trade envoy since 2001 "with complete and absolute propriety and integrity," the palace said.
In a statement issued Sunday, Ferguson, 50, apologized for the incident.
"I very deeply regret the situation and the embarrassment caused," the statement said. "It is true that my financial situation is under stress, however, that is no excuse for a serious lapse in judgment and I am very sorry that this has happened."
The tabloid said its reporter and Ferguson met on two occasions, once in New York and another time in London.
In the heavily edited, roughly four-minute video, Ferguson appears to accept $40,000 as a down payment for a meeting with Andrew, then later discusses a wire transfer of the larger sum.
"If we want to do a big deal with Andrew, then that's the big one," she says.
When asked how she would receive the £500,000, she tells the reporter, "You send it to the bank account that I tell you to send it to."
"Then that, is then like you open up all the channels whatever you need, whatever you want ... and then you meet Andrew and that's fine. And that's ... when you really open up whatever you want. But then that opens up everything that ever you would ever wish."
The tabloid said Prince Andrew, 50, who has been the UK's special representative for international trade and business since 2001, was not aware of the deal.
In the video, Ferguson tells the reporter that Andrew "never does accept a penny for anything. ... He does not and will not and he is completely whiter than white."
In her statement Sunday, Ferguson confirmed Andrew "was not aware or involved in any of the discussions that occurred. ... The duke has made a significant contribution to his business role over the last 10 years and has always acted with complete integrity."
CNN's Lonzo Cook contributed to this report.