Egyptian bodybuilder Moustafa Ismail now holds the ‘biggest biceps’ title in the Guinness Book of World Records.

The record, however, is in doubt:

Guinness World Records spokesman Chris Sheedy told ninemsn the company was now reviewing Ismail’s title.

“Regarding the record for ‘Largest Biceps’, Guinness World Records is conducting new research with medical specialists to review this category and determine whether we may need to make any changes to the outcome of the record,” he said.

Mr Sheedy said Guinness did not run tests on Ismail to determine if his muscles were achieved naturally because “our role, so far at least, is simply to record extremes”.

“One of the biggest issues for us is that the public naturally expects Guinness World Records to report all extremes,” he said.

“So the largest upper arm circumference on a human being is of interest biologically and we are expected to know who those arms belong to.

“Of course, at the time of measuring we believed Mo had not been utilising any performance enhancing drugs, and he still very publicly claims this to be the case.”