Ident of a 10 contact RJ45 style connector with 8 + 2 contacts

I’m trying to find a plug that will fit into this RJ45 style socket.

The top picture shows 8 contacts just as you would expect from a RJ45 8P8C style socket, in fact you can plug a standard ethernet LAN cable into this socket and it mates perfectly.

The bottom picture is the same socket but it shows two extra contacts. These pins carry a voltage supply to an encoder.

I’m trying to source a compatible plug with 8+2 contacts but cannot find a reference to one anywhere so I was wondering if anyone recognises it as a standard part number?

Note that this isn’t a 10P10C connector.

I can buy a pre-made cable with this plug on one end and a circular M23 on the other but I would like to source the plug to make up my own cable.

Matt.