The lawyer, Khalil Dulaimi, was responding to Iraqi President Jalal Talabani who said in a state television broadcast on Tuesday that Saddam had admitted he ordered the killing of the Kurds in northern Iraq.
"There was no confession from the president and the investigation of this case does not incriminate the president at all," said Dulaimi on Thursday, who is based in Baghdad and still regards Saddam as the president of Iraq.
"If it is proved that a certain judge has informed Mr Talabani on the process of the investigation, this judge must resign immediately," Dulaimi said in a statement on Thursday.
Dulaimi rebuked Talabani for his remarks, saying they meant "there will be no chance of a fair and clean trial."
"If it is proved that a certain judge has informed Mr Talabani on the process of the investigation, this judge must resign immediately"
Saddam Hussein's lawyer
"Mr Talabani should not declare anything related to the secrecy of a legal process," Dulaimi said.
Talabani said an investigating judge "was able to extract confessions from Saddam's mouth" about numerous executions during his 24 years in power.
Saddam and seven other members of his government are due to stand trial in the Iraq Special Tribunal on 19 October.
They are charged with ordering a massacre in Dujail in 1982 following an attempt to assassinate Saddam Hussein in the town north of Baghdad.