Child custody & support - thailand

My brother got married to a Thai national in May last year and in September they had a beautiful baby boy called Ryan. They have been living separately (he lives in the UK, she lives with Ryan in Thailand) for the last year whilst he is working 7 days a week to raise the money to bring them over to the Uk to live. He regularly sends her money to meet their needs (maintenance, hospital fees etc) and he pays the rent on the apartment in thailand where they live. He travels to thailand to viit them 3-4 times a year and contacts them every day by phone. Unfortunately, his wife has started making unreasonable demands on him for money and has threatened to leave him if he doesn't meet her demands, saying that he'll never see his child again. What rights does he have with regards to access and potential custody of his child if she carries out her threats ? Could anyone give me some advice ?

[Law200]

She cannot deny visitation and access--there or in the UK etc. That is an idle threat...WLD could help enforce if need be.