Take a look at the Trehane nursery webpage http://www.trehane.co.uk/kb_results.asp?ID=7

5 years is a bit of an inbetween age for a camellia - I'd say it is still a young plant and should probably be cut back straight after, before growth starts, but it may respond to a later pruning. Either way prepare for it to sulk next year in the matter of flowers.

The best way to deal with the camellia is to shorten a few of the shoots here and there but not all over,and then again next year on the shoots you have not shortened this year, by doing so you will ensure the camellia has flowers for the next two years and thereafter it will bloom magnificently again, do the shortening after the flowering has finished, water well during long dry periods so flower buds are well formed.

Thanks for you useful comments...do you think staking it would help as the main central branch seem to be pulling forward...therefore the other branches are following the descent.

I can't see that it would hurt - try to get a proper tree stake that will take the weight for a few years. Don't tie the branch too tight to the stake, and use a rubber tree tie for the main stem and soft natural twine/string, rather than plastic or wire, for branches. I'm growing a camellia against a wall and put in cordon wires last week and tied the branches up - it's only a baby (6 months out of the nursery) and needs a bit of help to stand up.

Cordon trained....what a good idea...this one is against a fence so I could achieve that...I did that with a Fremontodendron a few back years back with some success. Thank you all for the advice and ideas...
Happy gardening for 2015