my cousin sold his bitcoin to a guy in Thailand and that person made direct payment to my cousins bank account in Singapore from his Thailand bank but now the bank in Singapore is asking my cousin to produce his income source and has freeze that transaction money in his account. my concern is does the bank have that authority to stop my cousin from taking money out from his account and give such reason or excuses ?
is there any legal solution ? is it possible to sue the bank ?
banks may require for anything.
if they can not prevent it at all they can try to delay receiving funds.
anyway, a reason could be the following: that guy who sent money to your cousin was a suspicious one and that's why bank stops the transfer.
the only way is to be honest with a bank if your cousin lies then sooner or later it will be revealed.
the best advice is to explain everything including negotiations about btc purchase deal (and attach dialogue screenshots).
just make it transparent for them