My ear was caught by a mention of the need to fasten up an investigation and the difficulties this presented. It would appear that this comes from computer and telecommunications jargon. There is a lot of discussion of ways to fasten up your computer speed, your internet speed, and so on. I suppose that in this situation where what is crucial is the speed at which the computer functions, the data travels, the whole system operates, it is understandable that such a verb form could appear. It now seems to have generalised, moving away from devices and networks to any process or operation. We can expect more fastening up in the future.
There is a tendency to create new verb forms by adding little particles to an existing verb but it is more unusual to work with an adjective. This one is useful in that it fastens up the communication of the idea of the need for speed. The alternative would be ‘to increase the speed of’ and who wants that!