BACKGROUND:
These are ex Australian Federal Police customised "Record Of Interview" equipment panel sockets. This was back in the day when voice recordings with "persons of interest" were made using special cassette based machines which were designed so that the equipment and recording media was "tamper proof" and not readily accessible externally without the proper equipment, using techniques such as recording onto the cassette tape using a non-standard track layout (put the cassette into a "normal" machine and you would hear nothing) and additionally part of this design philosophy dictated the use of unusual input & output connectors so that an "ordinary" plug couldn't be inserted to transfer recordings off the equipment ... this is one of those unusual connectors.
Yes, it is of the mini DIN type but the socket configuration is not your usual 5 pins in a circular pattern but instead 2 pins on one side and 3 pins on the other, with one of the 3 pins offset from the other two pins. Central locating rectangular slot and at the edge of the connector front.
I have seen other electronic equipment use this type of 2 + 3 pin mini DIN connector but not often, it isn't in widespread use!
UNIDENTIFIED MANUFACTURER - Mini DIN Female Connector
Country of origin is unknown (not indicated anywhere on the socket)
5 pin (arranged as 2 + 3 pins with 1 of the latter 3 pins being offset from the other 2)

Panel mounting
Female
Thermoplastic body
Solder cup terminals
Comes with the original mounting bolts/nuts

COSMETIC CONDITION:
USED
Clean
Undamaged plastic body
Solder cups are relatively clean, no "dags" or previous wiring
Supplied in sealed, clear plastic individual packets