The tax payers is well within his rights to seek & inspect the warrant of authorisation, confirm the identities of authorized Income Tax Authorities mentioned on the warrant. The assessee can seek the telephone numbers of immediate supervisory officers of the search/survey party for the purpose of verification of genuineness.
In case, any doubts still persists then the Income Tax Department can be contacted on the following number 9013850099 for the specified purpose of confirmation of identities of officers/officials working in the Delhi region.