"He has bought nothing in Formula One. All he has bought is some show cars. He can forget it. He is wasting his time thinking about racing in Malaysia," Ecclestone was quoted as saying in Tuesday's Times newspaper.
British businessman Charles Nickerson, through Phoenix Finance, was revealed last week as the purchaser of Prost's assets. Prost was placed into liquidation in January.
Arrows boss Tom Walkinshaw said at the season-opening Australian Grand Prix that his TWR group would provide engineering back-up to a team aiming to take the 12th and final slot on the grid.
The next race is in Malaysia on March 17 but Ecclestone made clear that the Prost purchase did not give Nickerson the right to compete.
The Times also quoted International Automobile Federation (FIA) president Max Mosley as saying that the sport's governing body had yet to hear from Nickerson.
"We are waiting for an official communication from the purchasers of the Prost assets but they do appear to have major difficulties if they want to join the grid," he said.
Formula One is limited to 12 teams and, with Toyota's arrival this season, there are currently 11. A new team would have to deposit a bond of $48 million with the FIA before being allowed to compete.
