Reigning world champion Jenson Button has split with his girlfriend Jessica Michibata.

British daily tabloid The Sun said the 30-year-old decided to call time on their 18-month relationship shortly after the recent Monaco grand prix.

Japanese fashion model Michibata, 25, lives in Tokyo, and a friend of Monaco-domiciled Button is quoted as saying the “logistics” of the relationship “took their toll”.

“Just over a week ago Jenson reluctantly decided that his racing must be his main priority,” the source added.

A spokesman for Button confirmed: “Jenson is single again.  He and Jessica have gone their separate ways.”

After the chequered flag flew in Bahrain, McLaren ordered Jenson Button to shortly begin a 30-hour return to Europe. Flying to F1’s next stop, Shanghai, would have cost the reigning world champion just five hours in the air, and only a couple more hours would have had him relaxing in his Japanese girlfriend Jessica’s native Japan.

But McLaren wanted Button, 30, to instead complete the 21,000 kilometre marathon for just a single working day at the wheel of the sophisticated driver simulator at Woking.

He will then fly from the UK back to Asia for a holiday, prior to completing the journey to China for round four next weekend.

“Thirty hours travel for one day,” Button smilingly contemplated before leaving Kuala Lumpur. “But it will be worth it, hopefully.”

After winning in Melbourne, Button comparatively struggled in Malaysia, climbing to eighth on Sunday while his teammate Lewis Hamilton finished a highly-commended sixth from lower on the grid.

Button is struggling with the balance of the MP4-25, while McLaren want him to hone the latest developments that are due to be added to the package in Shanghai.

“The great thing is our car is improving all the time, but I’m still not 100 per cent happy with its balance,” the Briton said.

“Hopefully we can sort out some of the problems in the simulator. It’s a long way back but they wouldn’t be sending me unless there were a few things to test.”