Another AAP legislator, Sharad Chauhan, was arrested along with five others here on Sunday in connection with the suicide by a woman party worker, police said.
The woman, Soni, committed suicide on July 19 after being allegedly harassed by Ramesh Bhardwaj, a supporter of Chauhan.
Those arrested include a suspended Assistant Sub-Inspector in Delhi Police, Mukhtiyar Singh, who was probing the harassment case filed by Soni against Bhardwaj.
The others arrested were identified as Rajnikant, Amit Bharadwaj, Mohan Verma and Sanjay, a police spokesman said.
Chauhan's arrest prompted an angry reaction from Delhi's ruling Aam Aadmi Party, whose leader Ashutosh demanded to know if Prime Minister Narendra Modi had "lost his mental balance".
In a series of tweets, Ashutosh attacked Modi over the arrests of AAP MlAs.
"Another AAP MlA arrested. Has Modi gone madIJ Has he lost his mental balanceIJ If PM acts with such anger/vengeance, then is country safe", he asked.
Ashutosh said that instead of appreciating the "great job" done by AAP government in Delhi, Modi was arresting its legislators.
"Great initiatives are taken by Delhi government in education and health. Instead of praising (them), Modi is sending AAP MlAs to jail. Is (the) country safe in his handsIJ"
