Sri Lanka's just-concluded presidential polls did not comply with all the key benchmarks for democratic elections, the Commonwealth observer team has said citing "unequal contest with extensive, large-scale abuse of state resources".

In the absence of an independent Election Commission, Sri Lanka's electoral framework does not provide for the basic conditions for democratic elections, the group said in an interim report on the January 8 polls.

"Outcome of the 2015 election reflected the will of the people of Sri Lanka. It is however the view of the Group that the inadequate electoral and legal framework coupled with an unequal pre-electoral environment means that this electoral contest did not comply with all the key benchmarks for democratic elections".

The election campaign period was marked by an unequal contest with extensive, large-scale abuse of state resources, it said.

They noted comprehensive bias of state media against the campaign of Opposition Unity candidate; the use of military personnel and public officials to support the President's campaign; the use of Government monies, gifts and other inducements; and the widespread use of state-owned public transport by the incumbent.

The report added that incumbent Mahinda Rajapaksa's challenger Maithripala Sirisena received little to no coverage in the state media in clear contravention of the provisions.

Significant instances of violence in the campaign period had credible links to political party office bearers and created an atmosphere of fear and intimidation with concerns about potential violence on election day.

Commenting on the polls day, the observers noted, Voters appeared to exercise their franchise freely with the bulk of voters turning out in the firs half of the day, allowing for a smooth and timely closing of the polls.

Vote counting was conducted transparently, with counting officials working diligently and with dedication into the early hours of the morning. Domestic observer groups were allowed access to vote counting centres for the first time at this election, the Commonwealth observers said.

In a stunning verdict, Lankan voters ousted Rajapaksa from power after a 10-year rule and chose in his place his one-time minister Maithripala Sirisena, who led a revolt and defected to the opposition camp on the eve of announcement of the elections.