India, June 11 -- Two builders arrested on Tuesday in connection with the collapse of an illegal building in south Delhi's Saidulajab have told investigators that they were engaged through a verbal contract worth around Rs.1.10 crore to construct two additional floors on the structure, police said on Wednesday.

The accused - identified by police as Manish Khatri and Avinash Gupta - were arrested days after police apprehended building owner Karamveer Zaildar. Investigators said Khatri is a distant relative of Zaildar and was overseeing the construction work along with Gupta.

Police were informed that the agreement for construction was not formalised through any written contract and that work on the two additional floors had begun despite...