My wife is a learner. I went to drop her at work and upon returning back, police stopped me and asked for my documents, etc.
I put the Learner sticker on the car to help her while she is driving with her tutor.

Meanwhile, Police billed me 50k and after back and forth, I settled them with 20% of this sum.
They then removed the L stickers and told me to go and that I should never drive with the L since I am not.

Experienced drivers, is this actually illegal?

P.S: I have not been driving for long.
Also, please recommend official links I can read more on Nigeria and Lagos traffic rules. I can't seem to find much online apart from having materials (like fire extinguisher, etc) which I have all.

Also, please recommend official links I can read more on Nigeria and Lagos traffic rules.

Read traffic rules in Nigeria?
E be like you're an expatriate

When it comes to Nigeria policemen on roadblock, there's no rules. If you like have your complete papers, you can never be right in the eyes of an average Nigeria policemen on roadblock.

They're hawks looking for chicks to devour.

Instead of saying 20% why not just say 10k

You should have a copy of any evidence showing your wife is learning with the car in the glove box to present at any time.

I'm not aware of any law you've broken either way.

cyborg123:
You should have a copy of any evidence showing your wife is learning with the car in the glove box to present at any time.

I'm not aware of any law you've broken either way.

I showed the officer the original learner permit but he won't buy the idea

Just see it as your way of feeding the policemen for that day. We've all been there.

The police has used you to cash out. I'd suggest you get dashcam in your car to avoid any other police extortion.