The leaders have received nearly 100 SMSes over the week from two numbers, which were procured on forged documents, the Delhi police told a news agency.
"Of the two connections bought using documents of a gym instructor Manick Verma, one was transferred to another name using a different set of identification papers. Now we have detained a person named Yashpal.
"It was found that an identification paper belonging to Yashpal was used in getting one of these two SIM cards. This number was used for sending threatening and filthy messages," an officer is quoted as saying.
The politicians who received these SMSes include Minister of State for External Affairs Shashi Tharoor, Communist Party of India-Marxist (CPI-M) leader Brinda Karat and Congress leaders Rashid Alvi and Sandeep Dikshit among others.
Verma was questioned by the police but was let off as he was innocent. The gym instructor told the police that he lost his driving license some time ago and the police suspect that the culprit have found and used the license to acquire the numbers.