DNA evidence secured by Turkish prosecutors shows the bomber in Ankara who killed 28 people in a February 17 attack targeting a military convoy came from eastern Turkey and was not a Syrian refugee, Hurriyet newspaper reported on Tuesday.
The Turkish government had claimed the bomber was from northern Syria and was linked to the Kurdish People's Protection Units (YPG), a US-backed group fighting Islamic State in Syria. The YPG denied any links and said it never attacked Turkey.
However, a shadowy Turkish group known as the Kurdistan Freedom Falcons (TAK), claimed the attack two days later and said the bomber was a Turkish citizen from Van, in the east of the country.
TAK, which said the attack was revenge for ongoing Turkish military action in south-eastern Turkey, is often described as an extremist splinter from the armed Kurdistan Workers' Party (PKK). Some security officials claim there are still links.
The DNA evidence, which Hurriyet said was obtained after the bomber's father was arrested after the TAK claim, appears to support that the attacker was indeed born in Van in 1989 and was named Andulbaki Somer.
He appears to have registered as a Syrian refugee in Turkey using a fake identity.
The attack in the heart of the Turkish capital is the latest in a string of bombings to hit Turkey, including one in Istanbul last month which killed 12 German tourists.
Authorities have blamed Islamic State for the Istanbul suicide bombing as well as twin suicide blasts in Ankara in October which left more than 100 people dead.
Fighting with the PKK in south-eastern Turkey is intensifying since a ceasefire broke down in July, after holding for two years, with many hundreds dying in the clashes.
Since December, the military has stepped up operations against the armed group and imposed strict curfews in Kurdish districts which have drawn sharp criticism from human rights groups. Kurds in Turkey often complain of systemic discrimination.
Turkey does not make a distinction between the YPG in Syria and the PKK in Turkey.
At least 21 people have been detained in connection with the Ankara attack, the state-run Anadolu news agency reported.