Display Vendor Line Items

For Vendors is available in SAP a transaction to display open and/or cleared items, the transaction is FBL1N.

Also you can follow the path:

SAP Menu-> Accounting->Financial Accounting->Accounts Payable->Account->FBL1N Display/Change Line items 

Double clicking on displayed documents you obtain the details, including if the invoice is blocked for payment.

If you want to know the related material document, you could navigate to Environment->Document Environment->Original Document