Mike Ashley has launched High Court legal action against Newcastle co-owner Amanda Staveley, the financier who brokered the £305million Saudi-led takeover of the club in October.
The former owner, via his company St James Holdings, is bringing a claim against Staveley and her husband Mehrdad Ghodoussi, although the details have not yet been made public.
Staveley and Ghodoussi are yet to be served with proceedings but they are aware of the case. Representatives of both parties have declined to comment.
However, the legal action does indicate a deterioration in the relationship between Ashley and Staveley since the takeover was completed three months ago.