Swamp Harrier?

Is this a Swamp Harrier (Circus approximans)? 

This image was taken in Brisbane's western suburbs a few km's from the Brisbane River. 

The area is made up of tall woodland areas/state forest and some open fields/farm land, and of course the river is close by.

This bird was part of a pair circling around in gentle breeze early in the morning - over residental area/parkland. The estate is surrounded by the above mentioned environment.

It was with another bird - darker in colour, but that birds feathers were not as tattered.

? Is this an old male ?

It was difficult to tell which bird was bigger. 

They were both circling in the same manner and both had the distinct fingered wing tips that curled upwards at the ends. 

My wife and I have seen similar coloured birds in the areas for the last few years and initally believed them to be Brahminy Kites however upon captureing some photos I don't think they are - this bird lacks the distinct white head of the Brahminy Kite (althought I still believe the Brahminy Kites are in the area with their distinct reddy-brown back and white heads)

The bird in this image has light yellow eyes and it's cere is white.

I welcome any help, questions or comments on this one.

Kind regards,

ET