On 4G there are some Nokia 1020 , if you don't use internet (as Windows Mobile is fully out of support by years), whitin its 52mp Carl Zeiss Camera; or also the Nokia n9 (the platform which Microsoft bought, whitin the accord to use it exclusevely for 10 years), that has
that meego nice OS... (and also 12mp Carl Zeiss there).
The n9 had the edges shaped to enhance gestures (closing tasks within gestures), in 2012

.
https://en.wikipedia.org/wiki/Nokia_N9
https://en.wikipedia.org/wiki/Nokia_Lumia_1020
..or
https://en.wikipedia.org/wiki/Nokia_Lumia_1520
Ps: if you would consider looking for N9, check before the availabilty of the firmware, as those pages disappeared for the most.
For 80$ the 1020 is worth even just for the Camera, imho.
Spoiler:
To build the n9 OS, Nokia from the N900 made a N950 only for develoers, I mean... beatifulness
This was a rant

.
Thanks.
Edit: the EU version of the n9 has 4G (if I recall it correctly).
Also I don't know if even without internet, it should be considered secure anyway.