A student of class XII in his UP Board exam answer sheets has allegedly written "objectionable and threatening" words against chief minister Mayawati.

The incident came to light on Tuesday during correction of the answer-sheets at a checking centre here, dy controller of the centre AK Jain told reporters on Wednesday.

The copy has been sealed and sent to the Board head-quarters in Allahabad for necessary action, he added.

Lakhs of student have appeared for Class X and Class XII board examinations organised by the board in March-April this year.