Publishing a supplement to an investor document for a share issue on Thursday, Juventus reiterated that it had always acted in compliance with existing laws and it was fully collaborating with authorities.
Turin prosecutors said last week they were investigating the club and some of its senior managers, including Chairman Andrea Agnelli and Vice President Pavel Nedved, in a case centred around player transfers.
The prosecutors said they were checking whether Turin-based Juventus provided false communications to investors and issued invoices for transactions that never took place.
Italian financial police searched the club's offices last week to seize documents relating to player transfers between 2019 and 2021.
The latest search mentioned in the investor document was carried out on Thursday, a person with knowledge of the matter told Reuters.
Hit hard by the fallout of the COVID-19 pandemic, Juventus are seeking to raise 400 million euros in cash by selling new shares to cut debt and repair its finances.
In the supplement to the cash call prospectus, Juventus said prosecutors were also looking at its financial statements for the first half of 2021 in relation to Ronaldo's sale.
In August, Juventus reached an agreement to sell the Portuguese player to Manchester United for 23 million euros ($26 million), including 8 million euros linked to the achievement of specific performance objectives.
Juventus said at the time the deal entailed a 14 million euro hit on its results for the 2020/21 financial year, contributing to a record-high loss of 210 million euros.
A judicial source said prosecutors were checking the accuracy of figures in the club's financial statement relating to the transaction after a wiretapped conversation between club officials mentioned a document that called into question the fairness of the accounting.
Lawyers for Juventus and its managers said the new search did not reflect new charges being investigated, adding the warrant mentioned a document which had yet to be found.
The club said in the supplement to the share issue document that it did not believe the investigation and the searches constituted a "material adverse change" under a contractual clause that would allow the banking consortium guaranteeing the cash call to withdraw its commitment.
Juventus, one of 12 leading European clubs that made a failed attempt to set up a breakaway European Super League in April to beef up their finances, is controlled by Exor, the holding company of Italy's Agnelli family.
Exor has committed to subscribing to the cash call to keep its 63.8% stake.
Goldman Sachs, JP Morgan, Mediobanca e UniCredit CIB are the offer's joint global coordinators.
Juventus shares were down 0.8% by 1531 GMT on Friday against a flat Italian all-share index.
($1 = 0.8854 euros)
(Reporting by Elvira Pollina; editing by Jason Neely, Angus MacSwan and Mark Heinrich)
By Elvira Pollina and Emilio Parodi