Manchester United is still unable to fully restore its computer systems following a cyber attack.
The Red Devils confirmed the hacking on 20 November, but said it was not "aware of any breach of personal data associated with our fans and customers".
But, more than a week on from the attack club staff did not have access to email, and some other functions were also unavailable.
The UK's cyber security agency, the National Cyber Security Centre (NCSC) is now assisting the team.
A spokesperson said: "The NCSC is aware of an incident affecting Manchester United Football Club and we are working with the organisation and partners to understand impact."
In a statement the United reiterated they were not currently aware of any fan data being affected.
They added: "Following the recent cyber attack on the club, our IT team and external experts secured our networks and have conducted forensic investigations."
The club said it would not comment on who was "responsible for this attack or the motives".
This attack was by nature disruptive, but we are not currently aware of any fan data being compromised. Critical systems required for matches to take place at Old Trafford remained secure and games have gone ahead as normal.
Following the attack United informed the Information Commissioner's Office, as required.
They could face a fine from the data regulator if fan data is compromised as a result of the cyber attack.
Earlier this month, the NCSC's annual review showed the organisation defended the UK from more than 700 cyber attacks over the last year.
It noted a rise in the number of ransomware attacks - where attackers lock access to data until a ransom is paid - being deployed.
The NCSC said it dealt with more than three times as many ransomware incidents compared with last year and noted that criminals were changing their approach during such attacks to increasingly threaten to leak information publicly unless payment is made.