If employee voluntarily wish to contribute more than 12% then up to what percentage he can contribute?

Respected All, My Query:
Under EPF Scheme, if employee voluntarily wish to contribute more than 12% then up to what percentage he can contribute maximum.
If possible please give law reference.
Thanks

Dear Friend,
You may choose VPF option, where maximum contribution is up to 100% of his Basic Salary and Dearness Allowance. Interest is earned at the same rate as the EPF.

You Can contribute 88% On Basic And DA

Dear All,
Thanks for your reply..
Every one have different answers. Is there any fixed percentage ? What is the ceiling ?
Second thing if its 100% or 8o%, than if employees deductions reaches 50 % above than his gross will it be acceptable in Minimum wage act, as act says deduction should not be more than 50% of your gross.
Please clear my doubt.