Finding Deleted / Updated record statement from SQL Server transaction Log backup file
Method 1: If you want to find it from the transaction log backups you can use read the log viafn_dump_dblogto get the explicit information. On how to read and use this please refer Using fn_dblog, fn_dump_dblog

Note: 


  functn uses this extensively that every time fn_dump_dblog is called,
  it creates a new hidden SQLOS scheduler and up to three threads, which
  will not go away (and will not be reused) until a server restart.


Method 2: Using the default trace which is enabled by default in SQL server and it can be used to find various such information on altered objects etc. as explained in this article The default trace in SQL Server - the power of performance and security auditing

Method 3: You can use third party tool like ApexSQL Log(You can give it a try with Trial version , else for full verison you can go for purchase) which is a SQL transaction log reader for forensic auditing and rollback of malicious or inadvertent changes