Email, copying your manager:
Dear HR,
Re: our meeting by TEAMs on XXth yyyyyber at 11:22
You raised the issue of blah blah, wereny I confirmed blah blah and have agreed the following ongoing actions to be discussed with my manager copied on this email.
You also raised the topic of a meeting that you allege took place in December 2023 with former colleague Jane Smith who is no longer with the business. You alledged the this was in relation to blah blah blah. I have no recollection of this meeting nor any recollection of the facts you alledge were discussed at the time. At no time during my probation or since, was I absent without permission, nor did I do blah blah blah.
I am concerned that the current discussions about blah blah are being influenced by some incorrect information.
I would appreciate if you could look into this in my behalf and correct any information that may have been recorded in error on my HR file.
I look forward to this issue being resolved.
Only do this if you know you did not do what is being alleged at the time.. ie if the allegation is around not doing your hours and you were nipping out to get the kids from school or working while also doing childcare.. but you thought you had covered for it and no one noticed.. if there is evidence of the allegation, this could get awkward... also if the current issue is serious, insist that they stick to the facts and the issue at hand and do not attend meetings alone, if it's a teams call, you can answer and say that you prefer to have someone else join the call.
If the current issues alone, is likely to result in dismissal, start looking for another job and ensure you leave with a good reference.