Andrew Andronikou, administrator of the Championship (second division) English club, told Reuters on Thursday that Pompey had run out of patience and had made formal complaints to the English Football Association and Italian federation.
"They were due to pay the first instalment two weeks ago," he said.
"We've been listening to all sorts of excuses, such as missing bank details which were on the contract. It's come to a point where we've had enough."
Portsmouth, relegated from the Premier League at the end of last season after amassing debts of over 120 million pounds, agreed a 5 million pound deal in August for the German-born Ghanaian international midfielder to move to Genoa, Italy's oldest club.
Genoa then immediately loaned Boateng out to his current club AC Milan, who have a buy-out clause to make the move permanent.
Andronikou said Genoa had yet to pay Portsmouth any money, with the second of four instalments due in a week or so, and added that he would like to understand what Genoa had received from Milan.
"We complained last week on the 15th and got a response saying 'sorry, we mistook your bank details'," he said. "A week later, it doesn't look like the cheque has even hit the post."
Boateng, who helped Ghana reach the quarter-finals of this year's World Cup in South Africa, joined Portsmouth from Tottenham Hotspur in August 2009.
He scored five goals in 27 appearances for the south coast club but had a penalty saved in their 1-0 FA Cup final defeat by Chelsea in May.
In that same match, he also committed a foul on Chelsea's Michael Ballack that ruled the German captain out of the World Cup finals.
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