I wasn't certain if I should be sharing / posting the code hence didn't.

Code is ZJ8 and I found it on the Marriott West India Quay - London 'deals at hotel' page.

O2 Package at London Marriott Hotel West India Quay
The O2, South-East London is a state-of-the-art concert arena and you can set your visit to the O2 off in style.
Rates from: £61.60 GBP
Valid Through: 23 March 2012

I wanted to find all nights where the rate was near the 'from' price as so far I've found none.