Britney Spears' husband has bought her an engagement ring - nine months after they wed.

The pop singer was forced to buy her own diamond-studded band before their September nuptials because her then fiancé, Kevin Federline, was reportedly short of cash.

But former dancer Kevin kept his promise and has now splashed out on a replacement diamond bauble after saving up for the romantic gift, reports celebrity portal Femalefirst.

A source told America's People magazine: "I think it was because he wanted to buy her the diamond ring himself. She's having a platinum band with a round, single diamond set in a classic style."

The ring - from celebrity jeweller Cynthia Wolff - is said to be similar to the band the pop princess bought in the exclusive store last year.