A spokesman for the Dutch Public Prosecutor’s Office (OM) said Leijdekkers had been living in Sierra Leone for about six months.
They said he was known by the nickname Bolle Jos and that until recently he was suspected of living in Turkey.
Sierra Leonean authorities have not commented on the claims.
Reuters news agency reported that Leydeckers was spotted in Sierra Leone in January when the wife of Sierra Leone’s president posted a video on social media of a church service she attended with her husband.
According to Reuters, Leydeckers can be seen in the video. The BBC was unable to verify the footage.
Dutch police described Leijdekkers as “one of the key players in the international cocaine trade.”
A reward of $210,000 (£168,000) is being offered for tips leading to his arrest. It is reported to be the highest sum ever offered for a Dutch fugitive.
Europol, the EU’s law enforcement agency, has listed Leydeckers as one of the most wanted fugitives.
West Africa is a major transit point for the cocaine trade from Latin America.
January 17 of this year Sierra Leone recalled its ambassador from neighboring Guinea after seven suitcases believed to contain cocaine were found in an embassy vehicle.
Guinean authorities have seized a vehicle belonging to the Sierra Leone embassy and detained its occupants on suspicion of possessing “substances suspected of being cocaine,” Sierra Leone’s Foreign Minister Alhaji Musa Timothy Kaba said.
“In light of this serious development, the government has urgently recalled Sierra Leone’s ambassador to Guinea, Mr. Alimami Bangura, to Freetown to give a full report on the incident,” he added.
The recalled ambassador was not in the car and he was not arrested, the minister said.
“The ambassador’s involvement in this trade has not been proven,” he added.