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

% This is the RIPE Database query service.
% The objects are in RPSL format.
%
% The RIPE Database is subject to Terms and Conditions.
% See https://docs.db.ripe.net/terms-conditions.html

% Note: this output has been filtered.
%       To receive output for a database update, use the "-B" flag.

% Information related to '31.121.43.104 - 31.121.43.111'

% Abuse contact for '31.121.43.104 - 31.121.43.111' is 'abuse@ee.co.uk'

inetnum:        31.121.43.104 - 31.121.43.111
netname:        BTNET-CUSTOMER
descr:          FTIP005006229 IP MASTER
country:        GB
admin-c:        BY73-RIPE
tech-c:         BY73-RIPE
status:         ASSIGNED PA
mnt-by:         BTNET-MNT
mnt-lower:      BTNET-MNT
mnt-routes:     BTNET-MNT
remarks:        Please send abuse notification to btnet.abuse@bt.com
remarks:        Please send delisting issues to btnetdns@bt.net
remarks:        This range is statically assigned
created:        2019-09-05T08:39:40Z
last-modified:  2023-08-15T09:31:17Z
source:         RIPE

% Information related to '31.121.0.0/16AS2856'

route:          31.121.0.0/16
origin:         AS2856
mnt-by:         BTNET-INFRA-MNT
mnt-by:         AS12576-MNT
created:        2018-10-02T09:02:10Z
last-modified:  2019-05-22T12:43:09Z
source:         RIPE

% This query was served by the RIPE Database Query Service version 1.124.1 (BUSA)