Wealth Tax on NRO a/c balance?

Hello, I'm an NRI having NRO and NRE a/cs.

Please answer the following:

1) I know NRE a/c balances are exempt from wealth tax.

However, I was told that NRO a/c balances in excess of INR50,000 as of 31st Mar are subjected to wealth tax @ 1% in the hands of NRIs(subject to overall Rs. 30 lakh exemption limit). Is this true?

2) If it is true, then if I invest the NRO a/c balance in a debt/ liquid fund, would I be exempt? or are even mutual fund investments made out of NRO a/c balances subject to wealth tax in the hands of NRIs?

Thanks for any suggestions.