Former Israeli Prime Minister Ehud Olmert left prison early on Sunday after a parole board granted him early release from his 27-month corruption sentence.

Prison Service spokesman Assaf Librati said Olmert, 71, was whisked away by security and driven home after serving 16 months.

Librati said the terms of Olmert's early release stipulate that for the next few months he must do volunteer work, appear before police twice a month and not give interviews to the media or leave the country. Olmert will reportedly volunteer at a food bank and for a group that provides medical aid to needy families. However, President Reuven Rivlin could relieve him of the parole restrictions.

"We are very happy, a great burden has been lifted and a great sorrow and pain has ended," Eti Livni, a friend of Olmert, told Army Radio.

Olmert was convicted in 2014 in a wide-ranging case that accused him of accepting bribes to promote a real-estate project in Jerusalem and obstructing justice. The charges pertained to a period before he became Prime Minister in 2006, when he served as Mayor of Jerusalem and Trade Minister..

His departure from office in 2009 ended the last major Israeli-Palestinian peace efforts and ushered in the era of Benjamin Netanyahu.

Olmert was a long-time fixture in Israel's hawkish right wing when he began taking a dramatically more conciliatory line toward the Palestinians more than a decade ago. He played a leading role in Israel's withdrawal from the Gaza Strip in 2005 and became Prime Minister in January 2006 after his predecessor Ariel Sharon suffered a debilitating stroke. He resigned amid a corruption scandal that clouded his administration.

A gifted speaker, Olmert broke a series of taboos while in office — warning that Israel could become like apartheid South Africa if it continued its occupation of the Palestinians and expressing readiness to relinquish parts of Jerusalem under a peace deal.

He led his government to the Annapolis peace conference in November 2007, launching more than a year of ambitious, but ultimately unsuccessful US-brokered talks.

Olmert has said he made unprecedented concessions to the Palestinians — including a near-total withdrawal from the West Bank and an offer to place Jerusalem's Old City under international control — and was close to reaching an agreement at the time of his resignation.

Olmert was rushed to hospital with chest pains last month, but doctors ruled out a heart attack. A few days before that, Israel's Justice Ministry asked the police to investigate whether Olmert committed a "criminal offence" while behind bars.

It said a book Olmert is writing touches on "sensitive security issues" and that his lawyer was caught leaving the prison with a chapter on "secret operations" not approved by the censor for publication. Police searched the publishing house of the Yediot Ahronot newspaper, but not the paper itself, over the incident.

Justice Minister Ayelet Shaked welcomed Olmert's release, telling Army Radio that he deserved to have his sentence reduced and that "all in all his behaviour in prison was very good."

A few hours after his release, a somber-looking Olmert was seen walking around a shopping centre in Tel Aviv. A public relations company representing the centre released photos of the former Prime Minister in a clothing store, saying that people had greeted him and wished him well.