you could ask the technician. either way it will contain the same warranty.
The technician tells me that it is a new HDD. But how can I know whether the technician from the company is telling me the truth or has any links to people who provide devices from the gray market or if he could have taken the new hard disk from the company and giving me a refurbished one?
There are date codes all over the drive. Apart from the date on the label, there will be YWW or YYWW (Year / Week) date codes on the chips on the PCB. Some drives may even have a date code inked onto the casting.