Musa Susso made this revelation on Tuesday when he appeared as a state witness in the trial of former police chief Ensa Badjie and ex-police prosecutor Tijan Badjie.
Both men are standing trial on four count charges, including abuse of office, interfering with witnesses and defeating justice, but denied the allegations.
Mr Suso, who had been convicted and sentenced said, he could have won his case, if he was not denied access to witnesses.
“I was denied witnesses because the person they alleged that I lied against is the director of Prisons,” he said.
The ex-lawmaker said, he also had to withdraw appeal against his conviction because he was denied medical care.
Musa re-iterated that the former police chief on several occasions forced him to lie against former crime management coordinator of Gambia Police Force.
“You are under oath Mr Suso. Do you know the consequences of lying before this court?” defense lawyer Mboge cautioned. But Mr Suso maintained that he was stating the truth.
The case resumes today for the court to decide whether or not to accept a statement the state wants to tender as evidence.