Toyota acknowledges problems in the brakes of the 2010 model of its popular hybrid Prius. (Charles Rex Arbogast/Associated Press)

Toyota Motor Corp. will recall 270,000 Prius hybrid vehicles over brake problems in the United States and Japan, according to a top Japanese business newspaper.

The report comes after Toyota said Friday that it will investigate possible brake problems with its luxury Lexus hybrid in Japan and the United States. That announcement was made as the U.S. Transportation Department launched a formal investigation into brake problems in the 2010 Toyota Prius.

The newspaper Nihon Keizai reported that Toyota will soon notify Japan's Transport Ministry and the U.S. Department of Transportation about the recall, which would affect the new Prius hybrid model. The car went on sale in the United States and Japan in May 2009.

Toyota cannot announce a recall in Japan until it notifies the ministry.

No decision yet, Toyota says

Takayuki Fujimoto, a Transport Ministry official, said the government has yet to receive a recall notice from Toyota. Toyota spokeswoman Ririko Takeuchi said Friday that Toyota had not yet decided whether to recall the Prius.

"Nothing has been decided on whether we will recall or not," she said.

But Takeuchi said Toyota has launched a probe into the Lexus HS250h because it uses the same brake system as the Prius hybrid.

Takeuchi said that Toyota has not received any complaints about the Lexus HS250h model, and that the probe is to ensure safety.

Meanwhile, the U.S. Transportation Department probe will look into reports of temporary loss of braking ability on uneven road surfaces.

Toyota, already reeling from a massive recall involving faulty gas pedals, acknowledged Thursday there were design problems with the antilock brake system of the latest model of its gas-electric Prius hybrid.

Takeuchi said the automaker discovered design flaws in the new Prius and had corrected them for vehicles sold since January, including those shipped overseas.

But the company is still investigating how to inform people who bought their cars earlier. The model in question first hit showrooms last May. About 170,000 of the new model of cars were sold in Japan and 103,000 in the United States.

The revelation of problems in the company's flagship green car adds to the woes of the world's No. 1 automaker, whose reputation as a quality leader has taken a blow with the worldwide recall of 4.2 million vehicles with accelerator pedals that have the potential to stick.

About 180 complaints about braking problems in the third-generation Prius have been reported in the U.S. and Japan. The National Highway Traffic Safety Administration in the U.S. says there have been four reports of crashes.

Toyota Canada said Thursday it was aware of "a small number of isolated reports of inconsistent brake feel in certain 2010 model year Prius vehicles and we are investigating those reports."

NDP questions minister's reaction

MP Brian Masse, the NDP transport critic, accused Transport Minister John Baird of ignoring public safety concerns relating to Toyota.

"You have to wonder about the cozy relationship of Transport Canada, the minister and Toyota because public safety is not being investigated here in Canada," Masse told CBC News. "But abroad it’s actually going through extensive and comprehensive hearings."

But Baird's office rejected the accusations, saying Transport Canada “has been quite engaged with the U.S administration and Toyota on this file."

"Transport Canada officials have worked since the beginning with Toyota Canada to ensure corrective action is taken and that the safety of Canadians consumers is protected," said an email from the minister's office to CBC News.

Transport Canada was not made aware of issues related to the gas pedal recall until it was announced by Toyota.

Transport Canada said it has received five complaints relating to brake concerns on the 2010 Prius — all in the past two months.

The U.S. National Highway Traffic Safety Administration said two of the complaints involved crashes that resulted in injuries. Japan's Transport Ministry said Wednesday it has received 14 complaints since July about brake problems with the new hybrid.

The gas pedal recall applies to 270,000 vehicles in Canada and 2.3 million in the United States. Toyota said Thursday the U.S. recall could cost $2 billion US — $1.1 billion in direct costs and $770 million to $800 million in lost sales.

2 Ontario plants affected

The company halted sales in January of eight recalled models in North America, including the top-selling Camry and Corolla, until it fixes the issue. The Prius was not one of the models covered in the gas pedal recall.

Production at two Toyota manufacturing plants in southwestern Ontario was halted this week because of the recall.

The company made its recall cost projection in its quarterly earnings release, which reported a net profit of about $1.7 billion US in the quarter ended in December and forecast an annual profit of $880 million.

Toyota also raised its full-year sales outlook to 7.18 million units from 7.03 million. The revised forecast remains lower than the 7.57 million vehicles it sold in the previous financial year.

With files from The Associated Press