Doing an NVQ (they are called Diploma's nowadays, not NVQ) is difficult if it is not related to the job you, as it is worked based learning.
The assessments for this type of qualification are based on the evidence you produce in work, so for example, if it is business admin, you would need to be assessed/observed doing something related to the units in the NVQ. If it is care, then you would be observed delivering care to a patient or resident. If it is engineering, you would be assessed on something you have designed in the drawing office.
You can do an NVQ at college, but it's sometimes difficult to show your 'competence' if you are not in the workplace.
There has not been government funding for NVQ's for about 6 years. The funding is now for a while apprenticeship framework, which is the NVQ, a technical qualification (like a BTEC) and maths and English functional skills. All this is changing in April 2017.
The government will only fund apprenticeship frameworks (2/3 funding) if an employer has an annual salary bill of less than £3 million. Any employer that has an annual wage bill,of more than that, will have to pay for these qualifications themselves through a levy. The levy is paid through the tax the company pays.
If your organisation has to pay the levy, they will want to spend it on qualifications for its staff, or after 18 months they lose the money they have paid in. Worth talking to your employer about this.