Undefined Reference to 'SNMP_Decode_Packet - c++

Question

I am using CodeBlocks to compile a project I have inherited from an ex-colleague. One part of the project compiles correctly (it is split using build target files), the other part compiles with the following errors:
pinger.c: undefined reference to 'SNMP_Decode_Packet'
pinger.c: undefined reference to 'SNMP_Free'
The build log is as below:
[100.0%] mingw32-g++.exe -L..\pcap\Lib -o bin\Release\ZTC.exe obj\Debug_common\custom.o obj\Debug_common\dialog_common.o obj\Debug_common\setinifilename.o obj\Debug_gui\about.o obj\Debug_gui\browse.o obj\Debug_gui\gui_bootpd.o obj\Debug_gui\gui_bootpd_settings.o obj\Debug_gui\gui_conf_decode.o obj\Debug_gui\gui_conf_items.o obj\Debug_gui\gui_conf_top.o obj\Debug_gui\gui_dialog.o obj\Debug_gui\gui_gauges.o obj\Debug_gui\gui_log.o obj\Debug_gui\gui_main.o obj\Debug_gui\gui_move_win.o obj\Debug_gui\gui_pinger.o obj\Debug_gui\gui_pinger_settings.o obj\Debug_gui\gui_settings.o obj\Debug_gui\gui_tftp_dir.o obj\Debug_gui\gui_tftpd.o obj\Debug_gui\gui_ztp.o obj\Debug_gui\gui_ztp_settings.o obj\Debug_gui\tftp_cli.o obj\Debug_libs\conf\conf.o obj\Debug_libs\dump\dump.o obj\Debug_libs\event_log\eventlog.o obj\Debug_libs\GUI\Cmsgbox.o obj\Debug_libs\GUI\listview.o obj\Debug_libs\GUI\window.o obj\Debug_libs\lasterr\lasterr.o obj\Debug_libs\libtelnet\libtelnet.o obj\Debug_libs\linked_list\linked_list.o obj\Debug_libs\log\LogToMonitor.o obj\Debug_libs\md5\md5.o obj\Debug_libs\memdebug\cMemDbg.o obj\Debug_libs\mini_tcp4u\mini_tcp4u.o obj\Debug_libs\mini_tcp4u\tcp4u_exchg.o obj\Debug_libs\mini_tcp4u\udp4u.o obj\Debug_libs\ping_api\ping_api.o obj\Debug_libs\registry\registry.o obj\Debug_libs\scandir\scandir.o obj\Debug_libs\snmp\BUFFER.o obj\Debug_libs\snmp\DECODE.o obj\Debug_libs\snmp\ENCODE.o obj\Debug_libs\snmp\LIBFUNCS.o obj\Debug_libs\snmp\LOCALIO.o obj\Debug_libs\snmp\OBJECTID.o obj\Debug_libs\snmp\snmp_d.o obj\Debug_libs\snmp\SNMP_E.o obj\Debug_libs\snmp\sprint.o obj\Debug_libs\ztc_database\ztc_database.o obj\Debug_libs\ztp_api\ztp.o obj\Debug_libs\ztp_api\ztp_raw.o obj\Debug_main\cmd_line.o obj\Debug_main\main.o obj\Debug_main\outofthebox.o obj\Debug_services\async_log.o obj\Debug_services\bootpd.o obj\Debug_services\bootpd_console.o obj\Debug_services\bootpd_util.o obj\Debug_services\console_actions.o obj\Debug_services\ip_thread.o obj\Debug_services\ip_util.o obj\Debug_services\pinger.o obj\Debug_services\registry_thread.o obj\Debug_services\service_main.o obj\Debug_services\settings.o obj\Debug_services\start_threads.o obj\Debug_services\tftp_dbg.o obj\Debug_services\tftpd_main.o obj\Debug_services\tftpd_thread.o obj\Debug_services\tftpd_util.o obj\Debug_services\to_console.o obj\Debug_services\ztp.o obj\Debug_services\ztp_util.o obj\Debug\telnet.o obj\Debug_res\resource.res -lGdi32 -lcomdlg32 -lcomctl32 -lwpcap -lws2_32 -liphlpapi -Wl,--subsystem,windows -mwindows
obj\Debug_services\pinger.o:pinger.c:(.text+0x2ca): undefined reference to SNMP_Decode_Packet'
obj\Debug\_services\pinger.o:pinger.c:(.text+0xc98): undefined reference toSNMP_Free'
collect2.exe: error: ld returned 1 exit status
I have tried moving the pinger.o file before and after snmp.o file which contains the SNMP_Decode_Packet and SNMP_Free functions to no avail, the above log is the default positioning.
I can provide more information if it helps.
It is probably a simple error but any help to solve the issue would be greatly appreciated.