COLOMBO (AFP) – Activist Premakumar Gunaratnam alleges he was marked for death by Sri Lanka’s security boss a decade ago.

The architect of his abduction went on to become president, but now the dissident has played a key role in the leader’s downfall.

Now 56, Mr Gunaratnam was snatched by armed gunmen from his home near Colombo, bundled into a white van, and driven away to a secret location where he was restrained, stripped and tortured.

Plainclothes men operating in unmarked vehicles seized dozens of other dissidents, journalists and opposition politicians in 2012.

Many were never seen again.

Mr Gunaratnam, a radical leftist who was about to launch a new political party, was one of the lucky ones: International pressure secured his unexpected release four days later.

Sri Lanka’s security forces were controlled at the time by Mr Gotabaya Rajapaksa – who later became president, oversaw the country’s worst economic crisis and last week fled the island before resigning after his home was stormed by protesters whom Mr Gunaratnam helped to marshal.

“He abducted me and wanted to assassinate me,” Mr Gunaratnam alleges. “But this is not personal,” he added with a wry smile.

Local media describe the activist as a “key mover” in building an ostensibly leaderless months-long protest movement that channelled frustrations over the economic crisis into a political revolution.

It brought about the downfall of a political clan that had once been adored by much of the country for ending its decades-old civil war, despite an international outcry over atrocities by government troops in the conflict’s final weeks.

Mr Rajapaksa’s ouster and hurried flight to Singapore were a “win for democracy”, Gunaratnam said, but added that the protesters’ mission would be unfinished until he returned to face justice in a Sri Lankan courtroom.

“He is one of the key responsible persons for the abductions and disappearances, and he is one of the responsible persons for war crimes,” he said.

Security forces allegedly abducted troublesome opponents so often during and after Sri Lanka’s ethnic war that being “white-vanned” became a euphemism for kidnapping.