Saif-al Islam Gadhafi, the son of former dictator Moammar Gadhafi, can and will be tried for crimes against humanity in Libya, International Criminal Court (ICC) chief prosecutor Luis Moreno-Ocampo said on Tuesday.

Moreno-Ocampo, who is currently in Libya visiting with the National Transitional Council (NTC) government, called the capture of Saif al-Islam a crucial step in bringing to justice those most responsible for crimes committed in Libya, and added that the ICC only steps in when the national system cannot and it is up to the Libyan people to try the one-time future leader of the country.

Saif is captured, so we are here to ensure co-operation, Moreno-Ocampo told reporters in Tripoli.

In May, we requested an arrest warrant because Libyans could not do justice in Libya. Now, as Libyans... decided to do justice, they could do justice and we'll help them to do it – that is the system.

Our international criminal court acts when the national system cannot act. They [the Libyans] have decided to do it, and that is why we are here -- to learn and to understand what they are doing and to co-operate.

The ICC issued an arrest warrant for Saif al-Islam, along with Moammar Gadhafi and Abdullah al-Senoussi, in June for crimes against humanity. The court charged the three with ordering troops to shoot and kill unarmed protestors during demonstrations against the government in February and March.

The United Nations-backed court's harshest penalty is life in prison, but if tried in Libya, Saif al-Islam could be sentenced death. Libyan leaders have promised Moreno-Ocampo, as well as the international community, that Saif al-Islam will receive a fair trial.

However, there is a chance that Saif al-Islam could be tried for more than just the crimes related to the Libyan revolution, and a domestic court could tie him to many of his father's abuses of power from the past decade or more.

After the capture of Senoussi, Libyan critics suggested that the former spy chief be tried for a number of crimes committed under the Gaddafi regime, including corruption, human rights abuses and terrorist acts.

Senoussi is believed to have been responsible for most of the crimes committed against the Libyan people during the 42 years of Al Gadhafi's rule and during the uprising. Al Senoussi is also well aware of the most sensitive dealings made by the former dictator inside and outside of Libya, and supervised most of the terrorist operations outside of Libya. He also participated in the economic and political corruption schemes that characterized the Al Gadhafi era and controlled most of the dealings of Libya between September 1, 1969 and until October 2011, The Tripoli Post reported on Sunday.

Senoussi was captured in southern Libya on Sunday, a day about NTC troops found and captured Saif al-Islam.