Sydney, Jan. 25 (ANI): An American man who admitted to plotting and scouting targets before the deadly 2008 Mumbai attacks and then co-operated with US authorities to avoid execution has been sentenced to 35 years in prison.

David Coleman Headley, 52, pleaded guilty in 2010 to 12 charges related to the carnage in Mumbai and a second plot to attack a Danish newspaper that sparked outrage over its publication of cartoons of Prophet Mohammed.

He convinced US federal prosecutors to let him live after he was caught on tape plotting the attack on the Danish newspaper after telling them all he had learned in seven years of working with Pakistani militants, news.com.au reports.

Former US attorney Patrick Fitzgerald, who brokered the agreement, said the information Headley provided 'saved lives', as he urged Judge Harry Leinenweber to be lenient rather than imposing the maximum sentence of life in prison.

According to the report, heavily-armed militants rampaged through Mumbai in November 2008, killing 166 people and wounding hundreds more during nearly three days of carnage in a prolonged assault on the Indian financial capital.

In a plot that reads like a spy thriller, Headley spent two years casing Mumbai, even taking boat tours around the city's harbour to find landing sites for the attackers and befriending Bollywood stars as part of his cover, the report said.

He was so eager to attack Denmark's Jyllands-Posten newspaper over its publication of controversial cartoons mocking Prophet Mohammed that he began working seriously on that plot two months before the Mumbai attack.

He also had Bollywood and one of India's most sacred Hindu temples in his sights as he began plotting a second India attack during a March 2009 surveillance trip.

Leinenweber said that while the damage that Headley had caused was "unfathomable", he decided to fulfil the government's request because the recommended 30 to 35 years "is not a light sentence" given Headley's age.

The Washington-born son of a former Pakistani diplomat and an American woman, Headley's Western appearance and US passport helped him slip under the radar.

Headley, who changed his name so he could hide his Pakistani heritage, joined Lashkar-e-Taiba, the group India blames for the attacks, in 2002, attending terror training camps five times in three years, the report said.

Co-conspirator Tahawwur Hussain Rana, 52, was sentenced to 14 years in prison last week for letting Headley use his Chicago-based immigration firm as a cover while working on the Denmark plot, the report added. (ANI)