Two real estate firms in Noida have come under the scanner of central excise department officials for allegedly evading service tax of over Rs 20 crore.

Recent searches carried out by excise officials at the premises of some of these builders resulted in recovery of incriminating documents giving proof of 'black money' being collected and routed by them, official sources said.

A case has been booked against Shubhkamna Buildtech Pvt Ltd and Better Option Propmart (BOP) Pvt Ltd, Greater Noida, among others, for allegedly evading service tax, they said.

Denying any service tax evasion, both companies, however, admitted that investigations are being held against them by officials of the Directorate General of Central Excise Intelligence (DGCEI) in response to a query sent to them by PTI.

Shubhkamna Buildtech said that DGCEI officials had visited their offices and pointed out certain irregularities in respect of payment of service tax.

"We have fully cooperated with DGCEI officials... Our group companies are committed to strict ethical and compliance values and we have initiated steps to ensure that there is no future lapse on our part in fulfilling our service tax obligations," it said in the statement.

BOP said the matter is under investigation by DGCEI officials although nothing had been established yet.

"However, we are a tax compliant company and regularly file returns and pay taxes. In case any demand is raised by DGCEI during the course of the investigation, the same will be paid by us," the firm said.

The amount of evasion by these companies is above Rs 20 crore, sources said, adding that they were scrutinising documents recovered during the searches.

Excise department officials are going after all such evaders after a first-of-its-kind amnesty scheme for service tax defaulters ended in December last year.

The Voluntary Compliance Encouragement Scheme (VCES), which was implemented from May 10 last year, was announced by Finance Minister P Chidambaram to allow service tax defaulters to pay dues without any penalty or late payment charges.

Under the scheme, a person was to make a declaration to the designated authority on or before December 31, 2013.