Family visitor visa

[zzhys]

We have applied successfully for family visit visa for my mother and son in 2011.
We now want them to visit us again over this christmas, I know time is short but they have three days fast track service in Kolkata. Do they still have to provide all the documents that they had submitted in 2011 as cirumstances have not changed or will they require to submit fresh documents.
The documents supplied originally were :-
Land documents, bank documents, pension information, college documents, residency documents and from us we gave our council tax, P60, telephone bills, utility bills, bank statement, rental agreement and invitation letter.

Please kindly advise.