% APNIC found the following authoritative answer from: whois.apnic.net

% [whois.apnic.net]
% Whois data copyright terms    http://www.apnic.net/db/dbcopyright.html

% Information related to 'MAINT-T-SYSTEMS'

mntner:         MAINT-T-SYSTEMS
upd-to:         dinesh.sundararajan@t-systems.com
auth:           # Filtered
descr:          Maintainer for T-Systems Singapore
admin-c:        CM2520-AP
tech-c:         DKS37-AP
country:        SG
referral-by:    APNIC-HM
mnt-by:         MAINT-T-SYSTEMS
last-modified:  2018-07-13T03:57:51Z
source:         APNIC

person:         Conie Mercader
address:        23 Tai Seng Drive
address:        #03-01  Deutsche Telekom Centre
address:        Singapore 535224
country:        SG
phone:          +65-6510-6109
e-mail:         conie.mercader@t-systems.com
nic-hdl:        CM2520-AP
mnt-by:         MAINT-T-SYSTEMS
fax-no:         +65-6510-6121
last-modified:  2018-07-13T03:28:29Z
source:         APNIC

person:         Dinesh Kumar Sundararajan
address:        23 Tai Seng Drive
address:        #03-01  Deutsche Telekom Centre
address:        Singapore 535224
country:        SG
phone:          +65-6510-4172
e-mail:         dinesh.sundararajan@t-systems.com
nic-hdl:        DKS37-AP
mnt-by:         MAINT-T-SYSTEMS
fax-no:         +65-6510-6121
last-modified:  2018-07-13T03:27:01Z
source:         APNIC

% This query was served by the APNIC Whois Service version 1.88.25 (WHOIS-AU2)

Search for
IP address lookups			Miscellaneous queries
-l	1st level less specific		-i	Inverse attributes	None admin-c admin-c,tech-c,zone-c author cross-mnt cross-nfy local-as mbrs-by-ref member-of mnt-by mnt-lower mnt-nfy mnt-routes notify nserver origin person referral-by rev-srv sub-dom tech-c upd-to zone-c
-L	All less specific		-T	Object types	All as-block as-set aut-num domain filter-set inet-rtr inet6num inetnum irt key-cert mntner peering-set person role route route-set rtr-set
-m	1st level more specific
-M	All more specific		Query hints Include "AS" in front of an AS number. Example: AS4808 Include "-t" (template only) or "-v" (template and description) in front of an object name to view the template Example: -t inetnum
-x	Exact match only
-d	Associated reverse domain