Andy Murray and girlfriend Kim Sears
Andy Murray and girlfriend Kim Sears flew back to London after he crashed out of the US Open. News of his earnings may cheer him up

Wimbledon tennis champion Andy Murray's business interests earned him a cool £6.3 million last year, quite apart from the £160,000 he picked up in prize money for his historic championship victory.

The sum represents income earned in sponsorship deals and profits generated by his official website, and do not include proceeds from his tennis matches.

The figure is up £3.6 million on 2011, according to a source with knowledge of Murray's accounts.

Murray, who is currently ranked number three in the world, has invested another £6m in property, according to the Sun newspaper.

The Scottish star recently rebranded his company 77 Management, commemorating the number of years Britain went without a Wimbledon winner since Fred Perry's title in 1936.

"The accounts are for the year ended November 30, 2012 and they report profits held in Andy's business at £6,371,821," the source told the tabloid.

'Sky's the limit'

Analysts estimate that his Wimbledon win could ultimately be worth in the region of £50m.

One sports marketing expert told Bloomberg News that "the sky really is the limit" for Murray, while another said he could "easily" command yearly earnings of £25m if he set his mind to it.

World number one Novak Djokovic makes an estimated £9m per year in endorsements.

Djokovic has won six Grand Slam championships, while Murray has now won two, along with an Olympic gold medal last summer.

Murray, 26, has been the runner-up in five other Grand Slam singles finals: the 2008 US Open, the 2010 Australian Open, the 2011 Australian Open, Wimbledon 2012 and the 2013 Australian Open, losing three to Roger Federer and two to Djokovic.

In 2011, under the tutelage of coach Ivan Lendl, Murray became the seventh player to reach the semi-finals of all four Grand Slam tournaments in a year.

One columnist for Forbes magazine, Patrick Rishe, said he believed Murray was perfectly capable of matching Djokovic's £9m per year, and could hit the £13m mark if he were to win a few more major titles.

Murray flew back into London with girlfriend Kim Sears after crashing out of the US Open to Stanislas Wawrinka in the quarter-finals at Flushing Meadows.