Another am I a British citizen question .....

I am not sure if my son is a british citizen so i thought i would post here ,ok here goes

My father come to england in the late 60's from Bangladesh and worked here and Then went back to Bangladesh in the 70's and married my mother and brought her over here and then went back on holiday bangladesh a few years later and I was born.My father at some stage went through the british citizenship ceromony and become british and I presume he passed it on to me via descent.
I went on holiday in Dec 2000 to Bangladesh and married my wife there and I come back to apply to bring her here in the uk,in the meantime before she was granted entry she had my son there in 2001.A few months later she come to the uk and its 2009 now so my question is is my son a British citizen or do i have to apply for him since he was born in bangladesh ?
I am pretty sure he needs to apply because I read somewhere that

" if one of the childs parents is a british citizen otherwise than by descent the child would automatically become a british citizen at birth"

but i thought i would ask anyway,thanks for any help in advance.

momo wrote:I presume he passed it on to me via descent.

If you are British "by descent", then you are not British "otherwise than by descent" and your son, born in Bangladesh, is not automatically British. If your son has been in the UK since 2001, then I believe that your son may be eligible to register as a British citizen under section 3(5) of British Nationality Act 1981.

thanks for the reply,cleared s few things for me