Portsmouth have been charged by the Football Association with breaches of rules in relation to Benjani's moves to and from the club.
The player joined Portsmouth from Auxerre in January 2006, before moving to Manchester City in January 2008.
Agent Willie McKay has also been charged after allegedly representing the selling club in both cases.
FA rules bar agents from acting for two different clubs in two consecutive transactions involving the same player.
The Zimbabwean striker joined Portsmouth for a then-club record £4.1m but did not score for the club until the final game of the season, when they won 2-1 at Wigan to preserve their Premier League status.
But he found his form in the 2007-08 season and was Portsmouth's top scorer when he moved to City for an initial fee of £3.87m, after a long drawn-out transfer saga.
A statement on the Portsmouth website said the club denied any wrongdoing.
"We did not pay an agent when Benjani joined from Auxerre, and his transfer to Manchester City was approved at the time by the Premier League and the FA's compliance unit," it said.
"This is nothing more than a technicality which we will strongly contest."
Portsmouth have until 29 August to respond to the charges.
Source: http://news.bbc.co.uk/sport1/hi/football/t...uth/7561783.stm