The blogger, who tweets under the pseudonym '@duncanjenkinsfc', has posted a series of emails between himself and Chang that show the deterioration of their professional relationship.
According to the posts, Chang made contact with the blogger - known as 'Sean' - in a bid to stop him posting about potential transfer deals, as it was costing the club money.
Chang, who joined the club in the summer, requested a meeting in Deansgate, Manchester, which 'Sean' attended.
"[Chang] told me LFC had been involved with difficult negotiations with Roma over the transfer of [Fabio] Borini," said the blogger.
"He claims Roma asked for absolute discretion from LFC, that if news of the proposed deal got out Roma's fans would be unhappy about the sale of a young Italian international."
'Sean' claims that Chang made a number of threatening comments towards him when he did not comply with Chang's demands, and even had knowledge of his father's business dealings.
The reported threats included "dog shit" being posted through his door and claims that he would have to move house as "football fans are crazy".
'Sean' went on to explain how Chang suspected a mole within the club, but was told how 'Duncan Jenkins' was just a character.
"This went on for a while and I explained how Duncan worked, that it was all a big ruse," the blogger added.
"I asked him why on earth were the club so upset/obsessed with me about Duncan, why all this nonsense."
A spokesman for Liverpool said that the club are aware of the allegations but refused to make a statement.