As far as I can see, the paper doesn't say anything about the direction of gene flow. It might have been either way, I suppose, considering how active Great Britain was in the Far East during colonial times. Two of the British individuals mentioned in the abstract below are from Cornwall and one is from Kent.
Abstract: Nucleotide sequence differences on the whole-genome scale have been computed for 1092 people from 14 populations publicly available by the 1000 Genomes Project. Total number of differences in genetic variants between 96,464 human pairs has been calculated. The distributions of these differences for individuals within European, Asian or African origin were characterized by narrow unimodal peaks with mean values of 3.8, 3.5, and 5.1 million respectively and standard deviations of 0.1-0.03 million. The total numbers of genomic differences between pairs of all known relatives were found to be significantly lower than their respective population means and in reverse proportion to the distance of their consanguinity. By counting the total number of genomic differences it is possible to infer familial relations for people that share down to 6% of common loci identical-by-descent. Detection of familial relations can be radically improved when only very rare genetic variants are taken into account. Counting of total number of shared very rare SNPs from whole-genome sequences allows establishing distant familial relations for persons with 8th and 9th degree of relationship. Using this analysis we predicted 271 distant familial pair-wise relations among 1092 individuals that have not been declared by 1000 Genomes Project. Particularly, among 89 British and 97 Chinese individuals we found three British-Chinese pairs with distant genetic relationships. Individuals from these pairs share identical by descent DNA fragments that represent 0.001%, 0.004%, and 0.01% of their genomes. With affordable whole-genome sequencing techniques, very rare SNPs should become important genetic markers for familial relationships and population stratification.
Al-Khudhair et al., Inference Of Distant Genetic Relations In Humans Using “1000 Genomes”, Genome Biol Evol (2015), doi: 10.1093/gbe/evv003