Welshman Tom, the son of former England batsman Matthew Maynard, also featured for Glamorgan and was tipped as a potential future England batsman.
British Transport Police confirmed he was struck by a London Underground train on the District Line at Wimbledon Park station early this morning.
45 minutes beforehand police were trying to apprehend him after seeing him driving 'erratically', a spokesman confirmed.
"At approx 4.15am on Monday, 18 June, officers stopped a vehicle after it was seen being driven erratically in Arthur Road, SW19," the statement read.
"The male driver of the vehicle - a black Mercedes C250 - made off on foot. Officers were unable to locate the man.
"At approx 5.10am the body of a man fitting the same description was found on tracks near Wimbledon Park station."
The incident is being treated by the police as non-suspicious.
Last week he was disciplined by Surrey for being out late during a Championship match against Sussex in Horsham.
A Surrey Cricket statement read: “Surrey County Cricket Club and ECB can confirm that batsman Tom Maynard has been confirmed dead by the Metropolitan Police.
“As a mark of respect to Tom, Surrey’s Friends Life t20 game against the Hampshire Royals at the Kia Oval that was scheduled for this Wednesday (June 20th) has been postponed.”
Surrey chairman Richard Thompson said: “Our thoughts at this awful time are with Tom’s family and friends and all those that were close to him.
“Tom Maynard was a prodigiously talented young batsman who had made an incredible start to his career and was clearly destined for far greater things. The impact Tom made in such a short period of time for Surrey CCC spoke for itself.
“There is a profound sense of loss at the passing of Tom. To lose anybody at such a young age is an utterly senseless tragedy.”
ECB chairman Giles Clarke said: “This is a very sad day for everyone connected with Surrey County Cricket Club and for Glamorgan County Cricket Club. Tom was a player of enormous potential who had already represented England Lions and had an exciting future ahead of him.
“Our hearts go out to the Maynard family for their tragic loss and we send them and all Tom’s many friends and colleagues within the game our deepest sympathies.”
Maynard played for Surrey on Sunday, making seven runs off 17 balls against Kent in the Friends Life t20.
Maynard, a powerful middle-order batsman who could also bowl off-break, made his senior debut as an 18-year-old in 2007.
Following his father’s departure as Glamorgan director of cricket in November 2010, he opted to join Surrey.
He helped the Lions secure the Clydesdale Bank 40 title as well as LV= County Championship promotion, averaging over 40 in the three domestic competitions.
In winter 2011 he was part of the England Performance Programme and toured Bangladesh with England Lions.