Halford had been a member of the playing staff at Fratton Park since October 2010, until he left the crisis-ridden club for a move to Nottingham Forest.
The 27-year-old has now spoken out about ownership rules which he feels is the cause of many problems.
He told the Chichester Observer: "The ownership system needs to be looked at. These people have to be put under the microscope more.
"I just don't think any more clubs should be allowed to go through what Pompey are.
"I think the Football League and the Premier League need to maybe have a look at their test."