The MP was arrested at Hyderabad airport as soon as he landed to launch an indefinite fast. The police has taken Lagadapati to an undiscolsed location.
Reports suggest that the MP's supporters gathered at Rajiv Gandhi International Airport in Shamshabad tried to resist the arrest.
The Vijayawada MP had earlier threatened to go on an indefinite fast starting from Monday, Dec 14 protesting against the separation of Andhra Pradesh.
On Sunday, Dec 13, Lagadapati said he would meet chief minister K Rosaiah in Hyderabad.
"If the resolution is not moved I would undertake the hunger strike," he said.
Lagadapati was also the first MP to resign from Lok Sabha on Thursday, Dec 10 after the Centre's gave its nod for the creation of Telangana on Wednesday, Dec 9 night.