The 57-year-old was nabbed while strolling a Port Douglas beach about 8am on Thursday.

NSW detectives applied for Foster to be extradited to Sydney during a brief appearance in Cairns Magistrates Court on Friday.

He is expected to be escorted from Queensland on Monday before facing a Sydney court on Tuesday.

Hours before his arrest, the serial weight-loss scam artist posted about going on a diet and looking for love on social media.

"I am on a quest to lose those 20 kilos before Christmas so I may find a new love to kiss under the mistletoe," Foster wrote.

"I decided there is much I have missed being so overweight, for one thing I haven't seen my naughty bits in over 10 years, so this is all about reconnecting with an old friend, and hopefully making new ones."

Foster has been in and out of jail since 1995 for fraud offences including a multi-million dollar weight-loss scam.

He sparked turmoil for former British prime minister Tony Blair in 2002 when - acting as a financial advisor - he helped Blair's wife Cherie buy two discounted apartments.

In the same social media post, Foster acknowledged his checkered past.

"I used to say that I guarantee anyone who bought my Bai Lin Slimming Tea would lose five pounds. Well, PS4.95 including GST to be precise," he posted.

"Pay-back is a bitch."

Australian Associated Press