AML laws would make it illegal to send money to someone with documents that appear to be altered.
Clients need to get their docs verified up front. Far too many ignore the need for this until after they've made money.
The issue is two-fold.
First, many clients want to open and start trading in 5 minutes. Any broker that says "don't send money, send docs first and give us up to a week to check them" would lose a lot of potential clients.
Second, there are real cases where crimes are attempted using forex accounts. This can be money laundering, or can involve stolen credit cards.
For example: Two accounts are opened using stolen credit card info. Both deposit $100. The more-or-less hedge each other with risky trades. The first account is wiped out, the second one gets $200.
The second account (now with about $200) will try to come up with reasons to refund to a different source. If that fails, the initial $100 goes back to the card. Either way, suspicious docs pop up and about a week later, the first account does a chargeback because the $100 was not an authorized transaction. If the credit card wasn't refunded, a chargeback by the real owner could happen at any time.
In this scenario, the broker paying those profits is not paying money owed to a trader. Any payment made would be rewarding a criminal.
Of course, it's not going to be just 2 accounts with only $100 each. This will be done across a large number of accounts, all of which will generally have larger deposits.
If the original poster in this thread can get his docs verified by the regulators, I'm sure he'll get his profits. If not, then the broker did exactly the right thing by holding back the money.