The Top Gear presenter Richard Hammond today described how he had "flatlined" and had a 50/50 chance of surviving after suffering a 288mph jet car crash last month.

In his first interview since the accident, which happened as he filmed for the BBC motoring show on September 20, Hammond told the Mirror that he did not know what went wrong but had suddenly found himself "upside down and inhaling a field".

The presenter is recovering from a brain injury that caused short-term memory loss and, in the early stages of his recovery, caused him to regress to a childlike state in which he became obsessed with Lego and the card game Top Trumps.

"I felt mad as a bag of snakes," he said. "My mind was like a foreign place, nothing in it but blankness." He spoke of suffering "sharp, jagged, pointy pain", for which he was given morphine.

The Vampire jet car crash happened on Hammond's final run of a day of filming at Elvington airfield, near York. He was airlifted to Leeds General Infirmary, where it was found he had suffered a significant brain injury.

He told the Mirror surgeons had considered drilling a "bore hole" to drain the blood from his brain and relieve the swelling, but it had ultimately been decided that the operation would not be necessary.

"It was 50/50 what was going to happen. I may have been dead, I may not have woken up," he said. "Doctors use a points system. Fifteen is normal, three is a flatline. I was a three. I was that close to being dead." He added he was amazed that he had not needed brain surgery.

Today's Mirror publishes new pictures of a remarkably well-looking Hammond with his wife, Mindy, and daughters, Izzy and Willow.

The paper's reporter Victoria Ward told BBC Radio 4's Today programme that he was clearly still coming to terms with what had happened and would become quieter when the accident was mentioned.

Hammond said he realised that the accident put Top Gear under scrutiny because of the risks he and his co-presenters, Jeremy Clarkson and James May, take.

At the time of the crash, it was reported that he had spoken immediately afterwards, telling emergency workers he needed to film a piece to camera. He said he had no recollection of doing that, adding that his condition had deteriorated sharply soon afterwards.

It was reported today that Hammond had signed a new £2m deal with the BBC. A spokeswoman for the corporation would not comment on the amount, but confirmed that he had agreed a two-year contract before the crash.

The spokeswoman said the BBC could not confirm the return of Top Gear until it had received an update on his progress.