David and Victoria Beckham are spending thousands building an intruder-proof fortress garden in the grounds of their mansion. Picture: AFP

David Beckham is said to have netted R217 million from his image rights company last year, taking his earnings to around R633,000 a day.

The former footballer - who hung up his boots from the beautiful game four years ago - is one of the world's highest-earning retired athletes thanks to his image rights company, Footwork Productions Ltd, which reportedly scores him a staggering R633,000 a day. 

READ: David Beckham builds Harper a Lego Disney castle

According to The Sun newspaper, the 42-year-old star pocketed R230 million last year thanks to deals with the likes of H&M, Adidas and Haig Club Whisky. 

In the past five years, the former England football captain - who is estimated to be worth around R298 billion - is said to have netted dividends of around R81 billion. 

David and wife Victoria - who have children Brooklyn, 18, Romeo, 15, Cruz, 12, and six-year-old Harper - recently splashed out £6 million on a countryside mansion in Oxfordshire, south west England, and they are now spending thousands to build a rural retreat in the grounds. 

The showbiz power couple are forking out for a two-tiered outdoor space which will include an orchard containing 23 different types of tree.

David will also be able to try out a whole different ball game after he was granted planning permission for a 60ft croquet lawn, and the outdoor space will feature two vegetable patches and a natural swimming pool within a courtyard. 

In May, the ex-Manchester United star was said to be planning to purchase an island for Victoria to mark their 20th anniversary. 

David is said to have eyed up the 250-acre island of Bird Cay, in the South Berry Islands of Nassau, which could set him back as much as R126 million. 

A source said at the time: "The Beckhams, particularly Posh, crave normality for their family times. Photos of Victoria in her bikini are incredibly rare because she is now very conscious about her body.

"So David wanted to give her that gift of privacy to mark two decades since they first started dating, a place where she can be totally relaxed.

"They love being on Sir Richard Branson's Necker Island, so for David this was the logical next step. The Caribbean Islands are incredible, so they really are spoilt for choice, but Bird Cay is looking like the one."