Alesha Dixon
Alesha Dixon's brother John Lonergan is said to be in a serious but stable condition Toby Melville/Reuters

Alesha Dixon's brother met with a horrific car crash in Welwyn, Hertfordshire on Sunday (27 August). John Lonergan is said to have suffered serious injuries from the accident, which has left his friend dead.

According to The Sun, Lonergan's pal James Bartell died after the car they were travelling in lost control and ploughed into trees. Lonergan was seated in the passenger seat during the crash.

The Britain's Got Talent judge is "sick" after coming to know about the condition of her younger brother, who is "badly injured but is lucky to be alive".

Lonergan is admitted to a hospital in Stevenage, where he is said to be in a serious but stable condition.

"He is badly injured but is lucky to be alive," a source told the news website.

"He has several broken ribs and a broken collar bone."

"Although he will hopefully make a full recovery, he will have to come to terms with the death of his friend," the source said. "It's expected he will be in hospital for some time."

It is not yet known as to how Bartell lost control of his Ford KA. He is survived by his wife and two children.

Police are currently investigating the incident, which occurred just before 5pm on Sunday.

"I am appealing to anyone who witnessed the collision or the events leading up to it, to please contact me," PC Jackie Lister said of the crash.

"I am conscious that many drivers these days have dash cams fitted to their vehicles and may have captured the vehicle being driven immediately prior to the collision.

"If anyone has footage, this may prove useful to the investigation," he said and added, "Please contact me on Hertfordshire Constabulary's non-emergency number 101 so that I can review it."