'fixed' roof leak around chimney has reappeared

[Northman]

A friend had a leak in the roof that appeared to be from around the chimney. He had a chap in before Christmas who "did a bit of pointing/re-sealing around the chimney that he thought would solve the problem."
With the weather this week, the problem is back. Any thoughts on what the likely source of this leak would be?

 

[Wayners]

I had similar.
I paid to have new lead around chimney and that never stopped leak.
Got hose up on roof and no water came in?

To fix I used foam on the inside around. Fixed it...
My theory is high wind blows water through so making it air tight with foam stopped that.

I've been in 100s of lofts over the years and I found a percentage had water coming in yet looked fine. Can't really replicate wind and rain to test though

 

[Jurassicspark]

Without seeing the interior pictures, I would have said the brickwork is letting rain in. Assuming he checked the flaunching, the area of the leak suggests the flashing is not done correctly on the last picture.

 

[Northman]

Thanks both. The leadwork looks reasonably good to me as a layman. I did wonder about wind blowing in, as the leak is not consistent and particularly high volume. Here are another couple of internal pictures that suggest it might be brickwork or the top of the chimney letting water in. Rather tricky getting a picture of the top of the stack, though will try to do that.