My final hope to recover my 5 years old established account is over. I have received the following mail from BitcoinTalk team...

Thank you for your email.
After checking the entire history related to this account and based on the current investigation, there is simply not enough info to determine the true owner as the account appears to have been sold at some point possibly alongisde the private key for the address used to sign the message. Also, there's no guarantee that the website you mentioned was not hacked as well, therefore, it will not be used as a valid point in the recovery process.
Taking these matters into consideration, our final decision is that the account will be locked and you can continue using the alternative one you created.
Best regards,
Bitcointalk account recovery team