Two colleagues of a teacher, who was attacked at Kottarakkara in 2011, have agreed to undergo polygraph tests.

The two teachers, colleagues of R. Krishnakumar of Ramavilasam Vocational Higher Secondary School at Valakom, expressed their consent before the Ernakulam Chief Judicial Magistrate Court here on Thursday.

A third teacher refused to undergo the tests, while a fourth teacher did not turn up at the court.