Assuming you have only $200K, you want to buy a $1m investment property, buy can only borrow $500k due to LTV.
Possible solution is that you get the seller to inflate the price to $1.6m so that you can borrow $800,000K from the bank. In return, you take up a short term loan to make round trip of $200K + $600K (short term loan) through the buyer and then you retire the loan.
Disadvantage is of course you need to pay higher stamp duty, but the advantage is that you could now own a property.
The above is just a simplified example for discussion sake.