Mould in attic

[welshgirl]

Last November I had an issue with water leaking through my bathroom window whenever it rained. There was white mould in the attic above the bathroom right at the very end of the roof. I had the vents in the roof re-secured and a roofer said that a tile had blown and he took a large piece of lead(that's what I believe it was) up on the roof and said he had fixed the problem. We didn't have any more leakages through the bathroom window after that visit. He didn't treat the mould, he said once the water source stopped it would go away.
However I just went up to the attic and discovered the white mould as spread along the beam by about 2 feet. The mould is white and fluffy. It is staying on the beam and there is no sign of damage on the bathroom ceiling. I managed to scrap some of the mould away. It didn't feel wet but it hasn't rained for a while. Could this mould be from the original issue because it did take 5 weeks for the roofer to come to fix the problem or didn't he fix the problem and the water is still getting in but not finding its way to the bathroom window. I have scraped away some of the mould. Do I wait to see if the mould grows back?
Can anyone help with this issue.

[stoneyboy]

welshgirl ,
Scrape off as much mould as you can, place a fan heater (on 1/2 heat) blowing on the mouldy area for a couple of days and then treat the area with spirit based wood preservative.
end

[welshgirl]

Thanks for advice. If I do this and the mould grows back does that mean that the roof is still leaking?