Oxford University's department of statistics worked on the study.
The Government's hesitance to implement lockdown restrictions saw the number of those infected with coronavirus rise by 1.3 million in nine days, it has been reported.
According to an investigation by The Sunday Times's Insight team, Boris Johnson's delay in imposing measures saw cases rise from 200,000 on March 14 to 1.5 million on March 23 as the Government deliberated on the timing and scale of the lockdown.
The increase in cases during this time is shown in a study by Oxford University's department of statistics and Imperial College London's pandemic modellers.
The study used backward modelling to calculate that the rate of infection was doubling every three days on March 14 - the date it is believed the Government first agreed that lockdown measures would be necessary to curb the virus's spread.
Professor Peter Openshaw, a member of the Government's Nervtag (new and emerging respiratory virus threats advisory group), told the paper: "I think that critical period of delay made the big difference to the peak numbers, both of hospitalisations and of deaths.
"I think everyone would accept now in retrospect that if we'd gone for lockdown a couple of weeks earlier that would have greatly reduced the numbers of hospitalisations and deaths."
In a statement to the paper, a spokesman said the Government's strategy throughout the pandemic has been to protect the NHS and "save lives".
"It has been vital through this global pandemic to make interventions which the public can feasibly adopt in sufficient numbers over long periods."