Initially, Fifa's ethics committee provisionally suspended the 64-year-old pending full investigation into an alleged breach of ethics code in October.
However, Fifa's disciplinary committee found that Vorawi was still involved in FAT affairs during this period – constituting a breach of article 64 of the FIFA Disciplinary Code – and has therefore decided to ban him from taking part in any kind of football-related activity at national and international level for a period of three months.
A fine of 3,000 Swiss franc (Bt107,660) and a warning were also imposed.
The sanction against the Thai, who was made ineligible to stand for the re-election earlier this month due to his initial suspension that was extended in January, has the immediate effect.