At match point to Fognini, Tomic received serve holding his racket by its head, waving the handle vaguely at the ball as it flew past him for an ace.

Bernard Tomic sparked new tanking controversy at Madrid Masters after trying to serve with his racquet handle. https://t.co/0HAw8Si0wA

— 7NEWS Sydney (@7NewsSydney) May 4, 2016

Asked about the incident by the Gold Coast Bulletin, Tomic responded: "I don't care about that match point - would you care if you were 23 and worth over $10m?"

It is not the first time Tomic has been accused of showing a lack of effort.

At the US Open in 2012, the Australian was criticised by John McEnroe among others for his performance against Andy Roddick, while his 28-minute loss to Jarkko Nieminen in Miami in 2014 remains the quickest ever on the ATP Tour.

Tomic, meanwhile, was involved in a spat with Nick Kyrgios in March after he was heard on court disputing that his Davis Cup team-mate was too ill to play in their match against the USA.

Tomic's behaviour could put his appearance at the Olympics in Rio this summer in doubt.

There is no doubt his ranking, currently 22, will be high enough but International Tennis Federation rules stipulate that a player must be in good standing with their federation.

Tomic seemed to have turned a corner last year, climbing into the world's top 20, but the Fognini loss was his fourth in a row.