Saudi blogger Raif Badawi, who was sentenced to 1,000 lashes and 10 years in prison for insulting Islam, was awarded the European Parliament's prestigious Sakharov Prize for Freedom of Thought, a human rights prize, on Thursday.

The 31-year-old blogger, who was arrested in 2012, is an outspoken advocate of free speech whose vicious public flogging in January, when he was subjected to a first round of 50 lashes, triggered an international backlash.

In his announcement of the award, European Parliament head Martin Schulz called on Saudi King Salman to immediately release Badawi, denouncing his sentence and demanding that Riyadh live up to Europe's standards on the crucial question of human rights.

"This man has had ... imposed on him one of the most cruel penalties, which can only be described as brutal torture," Schulz said.

"I call on the Saudi king to immediately free him."

Badawi, who co-founded the Saudi Liberal Network Internet discussion group, was detained in 2012 on cybercrime charges.

Like most Saudis, Badawi is a Sunni Muslim, but his network had announced a "day of liberalism" and called for an end to the influence of religion on public life in the kingdom.

Badawi was subsequently arrested, and the website was shut down on the grounds that it criticized Saudi Arabia's notorious religious police.

Badawi was initially charged in 2013, and in 2014 a Saudi court sentenced him to 1,000 lashes and 10 years in jail.

His wife hailed the award as "a message of hope and courage" that came just two days after she warned that the next round of her husband's flogging sentence was expected to begin.