Can a UK bank request to see unredacted statement from a payee?

My father transferred some money accross to my bank account, which I no longer required and returned within a month.
TSB has frozen my account and told me this in a letter demanding I send payee’s bank statment. Which I had to request from my father and emailed accross to tsb. The bank statement from my father had been redacted with only payments to me showing. The bank is demanding to see the full statemnt.
Are they within legal rights to demand someone else’s full statement because they made a payment to me?

thanks