BAKU: Azerbaijaninfo-icon strongman Ilham Aliyev secured a fourth consecutive term on Wednesday in a snap election boycotted by the main opposition parties, exit polls showed.

An Aliyev victory was widely seen as a foregone conclusion with the Caspian state's downtrodden opposition unable to mount a serious challenge to his authoritarian rule.

In power for 15 years, Aliyev received 82.7 per cent of the vote, according to a government-commissioned exit poll, while the private French pollster Opinion Way said he garnered 86.5 per cent of the vote.

His position has been boosted in recent years by the steady influx of petrodollars into his government's coffers.

Opposition parties in the tightly controlled Caucasusinfo-icon nation have said the electionsinfo-icon are a sham and accused the authorities of preparing to rig the vote.

They have also condemned Aliyev's surprise -- and unexplained -- decision to hold the election six months ahead of schedule, saying it was aimed at shortening the campaign period and hampering efforts to prevent vote-rigging.

The authorities rejected the opposition's criticism, insisting the vote was free and fair.

A former KGB officer and communist-era leader, Aliyev senior had ruled Azerbaijan with an iron fist since 1993.

Ilham Aliyev was re-elected in 2008 and 2013 in polls that were denounced by opposition parties as fraudulent.

In 2009, he amended the country's constitution so he could run for an unlimited number of presidential terms, a move criticised by rights advocates.