Oksana: Why My Kid Needs $20k A Month

10/1/2010 1:05 PM PDT

Oksana: Why My Kid Needs $20k A Month

So you're wondering, how will Oksana Grigorieva spend $20,000 a month of Mel Gibson's money on an 11-month-old baby?

Sources connected with Oksana tell TMZ ... she has five reasons for needing 20k every 30 days:

-- Lucia is Mel's daughter, so she needs round-the-clock security
-- Oksana is in debt for more than $100,000 -- for legal fees, PR costs, etc -- and she needs to dig out of the hole
-- Oksana says Mel promised to take care of her and his daughter
-- They got accustomed to the Mel Gibson lifestyle
-- The baby costs a lot, with medical costs, food, clothing, gas for the car, etc.

So, we ask ...