A colleague is believed to have chopped off the head of a sub-contractor all because he thought his boss favoured the victim too much.

Kuala Selangor district police chief Supt Ruslan Abdullah said they have detained a suspect, also a subcontractor, Star Online reported.

The incident occurred about 4pm on Thursday.

Workers informed police they had found a human head at the bottom of a building under construction in Jeram.

The body was later found stuck to some scaffolding on the 10th floor.

A subcontractor, who had been working at the site for two years, went missing immediately after the incident. He was picked up today and is being held for questioning.