The 18-year-old was involved in the accident around 2 am Thursday at the family’s Villas do Mar estate, near the town of Troia which is just south of the capital, Lisbon.
Police said the teenager had been riding on an uneven piece of land when the bike rolled backward and fell on top of him. Firefighters had to pull him free of the wreck before medics tried to revive him, but their efforts proved in vain and he was pronounced dead at the scene.
The teenager’s body has been taken to the Institute of Forensic Medicine in the city of Santiago de Cacem for a post-mortem. Ballack has yet to make any official comment.
Emilio was the middle of Ballack’s three sons – born in 2002 to then-girlfriend Simone Lambe, who Ballack would marry in 2008 but divorced in 2012. Eldest son Louis was born in 2001, and youngest Jordi was born in 2005.
Ballack made 98 appearances for Germany, scoring 42 goals in the process.
After joining Chelsea for £18million in 2006, Ballack went on to make 167 appearances for the club, scoring 25 goals and registering 24 assists. It was the longest he had spent at a club.
Emilio, 18, pictured in his last Instagram post at the family’s holiday home just six days before Thursday’s accident in Portugal
During an interview with the Independent in 2009, Ballack revealed how he saw similarities with his own schooling in what was then East Germany.
He said: ‘You had to stand up in school and say some things and stand still, and wear some uniform.
‘Now I come to England and again my kids are in uniform, in a different way but they have to wear a uniform. In West Germany, you go to school everybody wears their own stuff.’
Ballack picked Portugal to rest and recover after having a tumour removed from near his spinal cord last year.
The former Chelsea and Germany midfielder had a growth discovered on his body during an MRI examination by a doctor, according to Bild.
The early detection proved fortunate for the 44-year-old and the tumour was removed before lab examinations cleared Ballack of any fears the growth was cancerous.