Monster Yamaha Tech 3 has released the following statement explaining the illness that has sidelined Jonas Folger since Motegi.

The German rookie withdrew from the Japanese round due to severe fatigue problems, initially thought to be a return of the Epstein Barr virus.

However medical checks have discovered 'a strain of Gilbert Syndrome', for which he is now being treated and will require a special diet in future.

'It’s a huge relief that we now have a clear understanding of the situation and how to move forward. The past 6 weeks have been very difficult for me, not knowing what’s happening or why my body shut down completely," Folger said.

"I’ve been living with elements of this since 2011 but I’ve always been able to overcome it and we never really knew what it was. It’s unfortunate that it took such a serious episode to finally diagnose the situation but I’m just thankful we now have some answers.

"I miss my team and all my friends in the paddock. I’ve received a lot of support from everyone on social media, not just fans but my competitors also and this means a lot to me.

"I’d like to thank everyone at Monster Yamaha Tech3 and all my sponsors for their belief in me, and messages of support. I will be back and stronger than ever, fighting at the top of MotoGP."

Folger was replaced by Kohta Nozane in Motegi, Broc Parkes in Phillip Island and Michael van der Mark for Sepang and this weekend's Valencia season finale.

The full statement from Tech 3 can be seen below.

'Monster Yamaha Tech3 is pleased to provide positive news for the fans and sponsors, regarding an update on Jonas Folger's condition.

''Jonas Folger has been busy visiting specialists in the Munich area to diagnose the illness that sidelined him from the Japanese GP in October, and subsequent races in Australia and Malaysia, and also this weekend’s finale in Valencia.

'On return from Japan, Jonas went in for tests at the TU Munich, Department of Sports Medicine and in addition had further examinations with Dr. Hierl and Dr. Burghardt. A strain of Gilbert Syndrome was discovered, a common genetic disorder affecting 2%-5% of the population, where the liver is unable to process toxins effectively.

'This has been an underlying condition that has plagued Jonas for several years but had never been diagnosed properly. Prior to the Japanese GP it had escalated to a point where his entire body shut down, rendering him bedridden.

'Jonas is currently going through a complete detoxification and cleansing of the body to help flush his liver and disperse of all toxins and moving forward he will need to adapt to a special diet.

'In addition, since his crash in Aragon, Jonas’ throat was damaged which affected his voice badly, he visited a specialist and they found a damaged nerve in the right vocal chords but recovery can take 1-2 years to return to normal.

'Jonas’ only objective is to return to racing as soon as possible with the Monster Yamaha Tech3 team.'