David Beckham is planning on buying Victoria an island for their 20th anniversary

Victoria Beckham and David Beckham. Photo / Getty

The retired soccer star is marking two decade since he first started dating the 43-year-old former Spice Girls singer, and is believed to be eyeing up a number of private islands as a gift for his long term partner.

According to sources, 42-year-old David - who has three sons Brooklyn, 18, Romeo, 14, and Cruz, 12, as well as five-year-old daughter Harper with his spouse - has all but settled on the 250-acre island of Bird Cay, in the South Berry Islands of Nassau, which will reportedly set him back a cool £7 million ($13,124,238.82 NZ) should he decide to splurge on the tropical paradise.

A close-up of Victoria Beckham's wedding ring. Photo / Getty

The decision to look into a private island reportedly comes as Victoria - who was known as Posh Spice during her time with the Wannabe hitmakers - "craves normality" for her family and wants to be able to enjoy a vacation without being hounded by paparazzi.

A source told the Daily Star Sunday newspaper: "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."

Necker Island. Photo / Getty

"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."

The island in question is said to include 4.75 miles of water frontage, with a stunning historic two-storey main residence which overlooks the ocean, as well as an extra five waterfront cottages.

Princess Diana with her kids during a holiday on Richard Branson's Island, Necker Island. Photo / Getty

The current owner of Bird Cay said of the property: "[It is] quite simply a tropical paradise tailor-made for a business retreat, a family compound or a stunning island resort."

David has not yet finalised his decision, however, and it is believed that the eight-acre island of Sandy Cay in The Abacos in the Bahamas, as well as the Toad Hall Estate in the British Virgin Islands, are also possibilities for the famous family.