A computer-implemented method for determining relatedness of a plurality of genomic sequences in a plurality of genomic samples, characterized in that the method comprises: (a) determining nucleotide sequence information from a first genomic sample and a second genomic sample, said sequence information including identified, mapped single nucleotide polymorphisms (SNPs) (303, 305, 306, 308); (b) comparing SNP information from step (a) with a reference set of mapped SNPs obtained from a reference panel of phased haplotypes that represent a population from which the samples were drawn, and obtaining linkage disequilibrium ("LD") log-likelihood ratios (LLRs) for a number of pairs of SNPs, wherein: (i) each pair comprises a SNP in the first genomic sample and a SNP in the second genomic sample, (ii) the pairs are within close proximity of each other, wherein the pairs are separated by 1 to 50 kb, (iii) the LLRs reflect the likelihood that the SNP information from step (a) derives from the same individual or different individuals; and (iv) the LLRs are each formed from a probability of observing a first SNP allele given an observation of a second SNP allele under two models according to Formula 1A and Formula 1B: P 1 A ∧ B = 1 2 f A ∧ B + 1 2 f A f B P 2 A ∧ B = f A f B wherein, P 1 represents the probability of observing alleles A and B together if both observations originate in the same diploid individual, ( f ( A ∧ B)) represents the frequency of A and B appearing together estimated from the reference panel. f, f represents the frequencies of A and B in the reference panel, and P 2 represents the probability of observing alleles A and B on independent unlinked chromosomes; (c) determining an aggregate likelihood that the first genomic sample and the second genomic sample are from the same individual by summation of LLRs obtained in step (b), wherein the LLRs are aggregated for pairs of SNPs by sampling pairs from sliding windows across each chromosome. (a) determining nucleotide sequence information from a first genomic sample and a second genomic sample, said sequence information including identified, mapped single nucleotide polymorphisms (SNPs) (303, 305, 306, 308); (b) comparing SNP information from step (a) with a reference set of mapped SNPs obtained from a reference panel of phased haplotypes that represent a population from which the samples were drawn, and obtaining linkage disequilibrium ("LD") log-likelihood ratios (LLRs) for a number of pairs of SNPs, wherein: (i) each pair comprises a SNP in the first genomic sample and a SNP in the second genomic sample, (ii) the pairs are within close proximity of each other, wherein the pairs are separated by 1 to 50 kb, (iii) the LLRs reflect the likelihood that the SNP information from step (a) derives from the same individual or different individuals; and (iv) the LLRs are each formed from a probability of observing a first SNP allele given an observation of a second SNP allele under two models according to Formula 1A and Formula 1B: P 1 A ∧ B = 1 2 f A ∧ B + 1 2 f A f B P 2 A ∧ B = f A f B wherein, P 1 represents the probability of observing alleles A and B together if both observations originate in the same diploid individual, ( f ( A ∧ B)) represents the frequency of A and B appearing together estimated from the reference panel. f, f represents the frequencies of A and B in the reference panel, and P 2 represents the probability of observing alleles A and B on independent unlinked chromosomes; (i) each pair comprises a SNP in the first genomic sample and a SNP in the second genomic sample, (ii) the pairs are within close proximity of each other, wherein the pairs are separated by 1 to 50 kb, (iii) the LLRs reflect the likelihood that the SNP information from step (a) derives from the same individual or different individuals; and (iv) the LLRs are each formed from a probability of observing a first SNP allele given an observation of a second SNP allele under two models according to Formula 1A and Formula 1B: P 1 A ∧ B = 1 2 f A ∧ B + 1 2 f A f B P 2 A ∧ B = f A f B wherein, P 1 represents the probability of observing alleles A and B together if both observations originate in the same diploid individual, ( f ( A ∧ B)) represents the frequency of A and B appearing together estimated from the reference panel. f, f represents the frequencies of A and B in the reference panel, and P 2 represents the probability of observing alleles A and B on independent unlinked chromosomes; (c) determining an aggregate likelihood that the first genomic sample and the second genomic sample are from the same individual by summation of LLRs obtained in step (b), wherein the LLRs are aggregated for pairs of SNPs by sampling pairs from sliding windows across each chromosome.