You do mean the whole body dont you gerkin?
Also, i think it depends on whether you intend to eat the body. I am sure you have to consume it within 18 months.
If its ashes though i think its quite legal...
I think actually you can. There is a thing called a writ of Habius Corpus, literally "possession of the body". If you obtain one of those I believe you literally have legal possesion of someone's remains. this occurs in cases where someone wants to be stuffed for example and not buried or cremated. You don't have to be buried on consecrated ground but there are often bye laws preventing you being buried elsewhere. I don't see that cryogenically storing someone is necessarily much different to having them suffed. ( no Cold Ethel jokes please :)
Well I keep ex-boyfriends' heads proudly mounted on my living room wall and nobody has ever picked me up over that. So a family member must be okay too.