Arkadiusz Wisniowski, a research fellow in social statistics at the University of Southampton, said that despite polls showing a majority of people in Scotland in favour of remaining in the UK, the odds on a Yes vote were "almost even" with just a "very slight tendency towards the status quo".
Voters north of the border will decide the future of the UK in the referendum, which takes place in seven weeks' time on September 18.
In a piece in the Washington Post Mr Wisniowski said that the "outcome of the independence referendum remains uncertain as the Yes and No campaigns enter the closing stretch".
He is involved in a project that has collected all polling data about the referendum so far, with the academic stating: "Our forecast suggests a close result, which might surprise some readers given that support for independence has never been ahead in the polls.
"However, this reflects the narrowing of the polls in the past few months, and our model picks up this trend - and projects it forward."
He states that "we cannot conclude with any certainty" what the result of the historic ballot will be.
"In other words, just two months before the referendum, the estimated odds of Scotland gaining independence against remaining in the UK remain almost even, with a very slight tendency towards the status quo," the expert said.
"Despite the preponderance of polling pointing towards a victory for the No campaign, our model suggests that the result is still too close to call. As the referendum fast approaches and the campaign intensifies, everything is still to play for."
A spokesman for the pro-UK Better Together campaign said: "With less than 50 days until we vote, the polls show a clear majority of Scots are saying 'no thanks' to independence.
"As we get closer to the referendum Scots are thinking seriously about the risks to our pound, pensions and public services. Independence isn't a risk worth taking.
"Although the polls are encouraging we are far from complacent.
"We will campaign tirelessly every single day between now and September 18, making the case for why the brightest future for Scotland is to remain part of the UK. We need everybody who is saying 'no thanks' to separation to get involved and do their bit."