Agent Matt Hart has been suspended for 22 months after placing almost 1,500 bets on rugby worldwide and depositing in excess of £660,000 into a betting account.
Hart, who works for Stellar Management and represents England stars Maro Itoje and Ben Te'o among others, will be unable to work in the sport until February 2020, having been found guilty of two breaches of betting regulations.
In a statement, the RFU said the panel found Hart guilty of "betting on the outcome and/or any aspect of an event and receiving part or all of the proceeds of such betting" which was contrary to World Rugby and RFU regulations and also of "non-cooperation" with a request for information from the RFU anti-corruption officer, which was contrary to RFU regulations.
The Panel of three also ordered the payment of the RFU administration fee of £500.
Alys Lewis, RFU anti-corruption officer, said: "This decision unequivocally demonstrates that any activity which undermines the integrity of our sport, and exposes players and rugby to potential integrity issues, will be treated seriously by the RFU.
"The sums of money involved and the frequency and duration of the betting, coupled with the lack of cooperation with the RFU's investigation, have all contributed to a substantial suspension from rugby union which is welcomed by the RFU."
The suspension will begin with immediate effect.