President Abdoulaye Wade had ordered the inquiry into a capsized government-owned ferry Joola off the coast of Gambia in September 26 2002 in which over 1800 people died, a justice ministry official said on Monday.
"A decision has been made by the highest authority to open a judicial enquiry on the Joola," the official said, confirming an earlier statement by Justice Minister Cheikh Tidiane Sy cited by media.
"I recently received instructions from the head of state to study the possibilities of opening a judicial investigation in Senegal to deal definitively with the Joola affair," the newspaper Le Quotidien quoted the minister as saying.
He noted that French authorities had already opened an inquiry into the case in the absence of one from Senegal, the paper said. Twenty-two of the victims were French nationals.
Senegal's judiciary closed the case in 2003 because the captain of the boat, deemed the main person responsible, was among those who died.
However France has issued international warrants for seven civilian and military officials in connection with the disaster.
Senegal's Joola capsized as it was traveling from Ziguinchor in the south to Dakar.
According to official toll, 1 863 people died with others missing but groups representing families of the victims say more than 2 000 died with only 64 survivors.
The toll surpasses that of the 1912 sinking of the Titanic in the Atlantic Ocean when around 1 500 people were killed.
More than Titanic
Paris police arrested one of them, maritime economy ministry official Gomis Diedhiou, who was head of the marine security office at the time, in October.
His passport was withdrawn and he is under judicial restrictions in France, a Senegalese judicial official told AFP.
French authorities however cancelled in June 2009 arrest warrants for ex-prime minister Mame Madior Boye and former armed forces minister Youba Sambou, a decision confirmed in January this year as they have immunity because of their duties.
The greatest maritime disaster on record was the torpedoing of the German liner Wilhelm Gustloff packed with refugees by a Russian submarine in the Baltic in 1945, when more than 9 000 people died.