The man, who was serving time for a $2.7 million fraud, simply showed guards the letter and walked free. He later changed his mind and turned himself back in to authorities.
NPR's Ari Shapiro says the statue underscores how much the U.K.-India relationship has changed since Mohandas Gandhi fought for independence from Britain nearly 70 years ago.
The 70-year-old, best known for the stadium rock anthem "Rock & Roll (Part 2)," was convicted for sex offenses during the 1970s and '80s against three girls between the ages of 8 and 13.
The prime minister's remarks follow the disappearance this week of three British girls who are believed to have flown to Turkey with the intent of joining the self-declared Islamic State.
The jury convicted the 70-year-old of six offenses, including attempted rape, four counts of indecent assault and one of having sex with a girl under the age of 13.
The Oscar-nominated star of the Alan Turing biopic The Imitation Game has joined actor and comedian Stephen Fry in calling for a blanket pardon of 49,000 men punished under long-defunct law.
The actor who most famously plays Mr. Bean wrecked the high-performance car back in 2011. Luckily, he wasn't seriously injured. But it did cost him $1.4 million to get it fixed.
Abu Hamza al-Masri was found guilty eight months ago of charges stemming from plots to kill tourists in Yemen to a plan to open a jihadist training camp in rural Oregon.