Plant ID please

Hi, can anyone identify this plant. It was in the garden of the previous owners my brother bought property from. It looks a bit familiar to me, but I just can't place it. The garden was full of vegetables as well as plants. I think the pictures are of the same plant.
Thanks in advance.

 

It seems to have a square stem, I wonder if it could be a type of mint ? Does it have aromatic leaves ?
Could also be Figwort maybe ... ??

 

Vegetables? Beetroot going to seed.

Has a slight look of Himalayan balsam.

 

Judging by those leaves, like Michael I'm wondering if it's a mint, or at least something related to them. But the size is throwing me a bit and I'm curious to know if the photos are giving a false impression of the plant being larger than it is. How tall is it roughly, @lovenature?

Nick

 

Thanks for all the suggestions. I can try and get another photo @Nikolaos to get some perspective.

 

I agree with @pete it could be beetroot gone to seed.