Falsified documents for employment tribunal claim

Hello to all on this forum.

I am currently in the process of taking my previous employers to court for age discrimination.

I was side lined from a postion due to my age. The position was given to a younger, less experience person.

I have been constantly requesting my HR performance documents and have now had them sent via the post.

However, these documents are not my originals and have been altered to indicate that I was not being earmarked for this position, but just assisting with it.

I can prove that these have been altered due to my previous documents are so very different and the most recent do not bear my signature. There are so many discrepancies with the most recent performance document, it is balatantly a falsifed document.

I have written to the judge and have contacted their solicitors. Is this a criminal matter, and if so when do I go down that route.

Any replies would be very welcome.