Simsons now works for the Latvian Association of Victims of Political Repression, an NGO with 10,000 members who were the victims of deportations and slave labor camps.
The document was also signed by KGB administration deputy chief Fyodor Myasnikov and former KGB General Sergei Kondrashev.
The document contains instructions on how KGB employees and Soviet elite OMON troops were to be dealt with after Latvia gained its independence. Simsons' signature guaranteed Latvian protection of their rights and also assistance in finding them jobs.
Former supreme council member Janis Lagzdins, who currently represents the People's Party in the Parliament, said the document has no legal force and that it has not caused Latvia any damage.
"But the truth of the history behind this agreement should be found out and explained to the people."
The commission is planning to investigate the circumstances in which the document was signed and what sort of obligations Latvia took as a result of this agreement with the former KGB.
It has been argued on many occasions since the restoration of independence that KGB staff and OMON troopers should have been expelled from the country when the rest of the Soviet armed forces were made to leave in the early 1990s.
But not all parliamentarians agree. Janis Jurkans, MP and president of the For Human Rights in a United Latvia parliamentary coalition, told the Baltic News Service that he categorically objects to setting up the investigation commission saying there are more important issues to be dealt with in the Parliament.
And there are speculations that many documents are in existence that could name and shame a lot of people.
"Russian President Vladimir Putin may one day get fed up with all of it and decide to throw us every KGB document there is, and then we will suffocate in the dust from shame and disgrace," said Jurkans.
The formation of an investigative commission was supported by Social Democrats, the People's Party, Latvia's Way, and For Fatherland and Freedom, while For Human Rights in a United Latvia's MPs voted against the motion.
For Fatherland and Freedom party members first initiated the commission by gathering the required signatures of 35 MPs.
The KGB document, which has been publicly available for some time in official archives, was first brought to the public's attention by an article in the Vakars Zinas daily on May 16. At first, Simsons denied he had any memory of it. Then he told journalists it was complete nonsense that any secret deals had been made between the supreme council and the KGB.
A similar flap arose in Estonia last year and the government there ruled that the document had no force.