Britney Spears reportedly invested her Pepsi earnings into Coca-Cola.

The American singer became the spokesperson for Pepsi in 2001 and joined fellow pop stars Pink, Beyoncé Knowles and Enrique Iglesias singing Queen's We Will Rock You in a TV advertisement. This deal is believed to have earned her a staggering $8 million.

TMZ claims to have documents which confirm Britney sold 574 shares for the rival fizzy-drink company in 2012, making a profit of $3,238.55. She also kept a total of 208 shares for herself.

While success came in from Coca-Cola there were no traces of Pepsi in her portfolio.

It wasn't all earning though as she lost $640.13 on McDonald's and $1,277.38 on Mexican grill restaurant Chipotle, which she regularly visits for a tasty snack.

In total the blonde singer netted $97,883 in stock earnings last year alone and has just less than $13 million of her conservatorship money in the market.

A conservatorship is a legal agreement in the US in which a guardian is appointed by a judge to look after someone's financial affairs due to either physical or mental limitations.

Britney's father Jamie Spears has been in charge of her finances since her breakdown in 2008. It was recently reported he wants a $16,000 allowance each month from his daughter's two-year residency in Las Vegas at Planet Hollywood.

After five years it is thought the legal agreement will stay in place until further notice. Jamie has also reportedly asked for more money from Britney's estate to cover the $1,200 per month costs of his rented office.

The pop star's attorneys are also seeking more money, demanding compensation for their work and requesting their fees are raised from 50 per cent to 80 due to Britney's "excellent financial status".