Maduro, who showed a photo of a white-plaster wall with marks that appear like eyes and a nose, said Chavez's face had briefly appeared to workers building a new subway line in Caracas in the middle of the night.
Speaking on state television, the president said: "My hair stands on end just telling you about it. Who is that face? That gaze is the gaze of the fatherland that is everywhere around us, including in inexplicable phenomena."
Maduro - who was elected president in April after the death of Chavez - has previously spoken of seeing the spirit of his idol several times, including in the shape of a bird.
The Venezuelan government has decided the body of former president Hugo Chavez will not be embalmed for permanent display, according to the country's information minister.
Ernesto Villegas wrote on Twitter that the option has been dismissed based on the advice of a Russian medical commission.
He said the government was told that Chavez's body would have to be sent to Russia for seven to eight months to be properly embalmed.
Acting President Nicolas Maduro announced last week that Chavez's body would be put on display, but on Wednesday said that now seemed "highly unlikely".
Venezuelan opposition leader Henrique Capriles said he will challenge the late Hugo Chavez's preferred successor for the presidency of the South American OPEC nation next month, setting the stage for a bitter campaign.
Capriles, a 40-year-old state governor, will face election favourite and acting President Nicolas Maduro. The pair have until Monday to register their candidacies for the vote on April 14th.
The election will decide whether Chavez's self-styled socialist and nationalist revolution will live on in the country with the world's largest proven oil reserves.
Opposition leader Henrique Capriles will run for president in Venezuela's April election and is expected to formally announce the decision later today, two sources in his camp said.
"There's a lot of negativity around, it's going to be tough, but we're going to do it", one of the sources told Reuters.
"Henrique's made his decision. He's not backing down."
Venezuela's centrist opposition leader, Henrique Capriles, said he was "evaluating" the election date ruling and has thanked the coalition for proposing his candidacy.
The Venezuela presidential election will be held on April 14, the country's election commission told Reuters.
Acting President Nicolas Maduro, the protege of deceased leader Hugo Chavez, is the favourite to win the election in a likely face-off with centrist opposition Governor Henrique Capriles.
Acting Venezuelan president Nicolas Maduro has asked the country's election authority to call a vote immediately.
Officials are expected to announce the election date on Saturday as the South American country appoints a permanent successor to Hugo Chavez.
Mr Maduro, meanwhile, also named the late president's son-in-law Jorge Arreaza as his vice president during his time as interim leader.
Nicolas Maduro has been sworn in as the interim president of Venezuela following the state funeral for Hugo Chavez.
Maduro held the post of vice president under Chavez and had been passionately backed as his successor by the late president.
With the queues to see Hugo Chavez's body still snaking through the capital, Venezuala said goodbye to the man who has dominated politics in the country for decades.
Some 30 head of state from around the world were among the mourners at his state funeral; many of them visibly emotional.
ITV News' International Editor Bill Neely reports from Caracas: