According to an official note, the number of emails being screened rose to 1,601 as on September 30 from 1,174 in the end of August--an increase of 36.4 per cent.
The note said 10,490 phones across the country were monitored by various security agencies.
The number of phones tapped in August stood at 10,648.
A high-level committee which confirmed the snooping orders issued by the Union Home Secretary saw 1,915 fresh requests from Intelligence Bureau, 11 from the Enforcement Directorate and 492 from Directorate of Revenue Intelligence.
The interception is ordered by various intelligence agencies, police forces and Army which is later confirmed by a Committee comprising Cabinet Secretary Ajit Seth, Telecom secretary R Chandrasekhar and Law Secretary B A Agarwal.
The Committee, which met here recently and confirmed the orders passed by the Home Secretary, cleared a fresh request for monitoring 876 emails by Intelligence Bureau and Signal Intelligence of the Army, the note said.
Already, 725 emails were being monitored by the two agencies under the Indian Telegraph Act.
IB topped the chart monitoring nearly 5,500 phones out of which over 1,900 requests were made in September alone and was followed by Andhra Pradesh Police which made 549 requests in the month besides keeping under surveillance 755 others, sources said today.
The number of phones monitored by the Army's Signal Intelligence has come down sharply from 1,100 phones to 286 of which 100 requests were made in September, the sources said.
The Committee, however, rejected six requests made by intelligence agencies and demanded more clarifications on the issue of public emergency or public safety in respect of orders passed for fresh interception and continuing it, the sources said.