The National Investigation Agency on Tuesday arrested the main accused in a 2010 case of a professor’s hands being chopped off for allegedly insulting Prophet Muhammad in a question in an examination paper, The Hindu reported.

The main accused identified as Savad had hacked off the right hand of TJ Joseph, a professor at Newman College in Idukki district’s Thodupuzha town, on July 4, 2010. Savad and other members of the now-banned Islamic outfit Popular Front of India were named as accused in the case.

On Tuesday, Savad was arrested from Mattannur municipality in Kannur district where he had been working as a carpenter, reported The Hindu.

On Wednesday, a National Investigation Agency Special Court in Kochi remanded him to judicial custody till January 24.

Savad and six others had attacked Joseph while he was returning home from a church in Ernakulam district’s Muvattupuzha. The attackers dragged the professor out of his vehicle and assaulted him and chopped off his hand.

Joseph, the head of the Malayalam department at the college, had selected a passage from a short story by filmmaker PT Kunju Muhammed to test students on punctuation. The passage that carried an imaginary conversation had sparked a controversy.

In July, a National Investigation Agency court in Kerala had convicted six persons in the case. They were held guilty of attempted murder, conspiracy and other offences under the Indian Penal Code and under the Unlawful Activities (Prevention) Act. The judge, however, acquitted five others citing lack of evidence against them.

During the first phase of the trial, 31 accused faced prosecution. Of these, the court had convicted 13 men and acquitted 18 others in 2015. So far, 19 persons have been convicted in the case, reported The Print. Out of these three are serving life imprisonment.