German carmaker Opel, a subsidiary of General Motors, found itself in the spotlight Friday, with the transport ministry demanding explanations for media reports alleging irregularities in the emissions values of some of its cars.

According to both the weekly magazine Der Spiegel and the investigative news programme Monitor on ARD public television, tests on a number of Opel's diesel models had uncovered "hitherto unknown devices" that deactivate filtration systems in the engines of two of the best-selling models, Astra and Zafira.

That meant that the models' emissions systematically exceeded norms.

In response to the revelations, a special committee set up in the wake of the massive engine-rigging scandal that has engulfed Volkswagen, "has invited" Opel to offer an an explanation, a spokesman for the transport ministry said.

Opel issued a statement denying it used the same emissions-cheating software that is at the centre of the VW scandal.

"Our software was never programmed to deceive or defraud," insisted the carmaker, which is just emerging out of long years of crisis.

"Emission control systems are highly complex integrated systems," Opel said.

"The various parameters such as engine speed, load, temperature and altitude play an essential role and are interrelated. Such a complex system can not be broken down into individual parameters. Interactions must be understood holistically, in combination with the prevailing conditions and the various areas of the control system," it said.

The government committee, which has in recent months analysed all diesel models similar to those involved in the VW scandal, has concluded that no similar fraud has taken place.

Nevertheless, in a certain number of vehicles, the emission control systems were systematically de-activated when the outside temperature dropped below a certain level.

This is only allowed under European rules to prevent possible accidents or damage to the engine.

In April, German makers, Audi, Mercedes, Opel, Porsche and Volkswagen, decided to voluntarily recall around 630,000 cars in Europe to remedy this problem.

According to Der Spiegel and Monitor, the Astra's emission control systems were only programmed to function at outside temperatures above 17 degrees Celsius, effectively meaning they did not function for a large part of the year.

VW was plunged into its deepest-ever crisis last September when it emerged that it had installed emissions-cheating software, known as defeat devices, into 11 million diesel engines worldwide.

Scandal-hit VW gives staff 3,950-euro bonus
Berlin (AFP) May 13, 2016 - German auto giant Volkswagen announced Friday it is giving its staff a 3,950-euro bonus for 2015, despite suffering huge losses due to an emissions-cheating scandal which sent shockwaves through the industry.

The pre-tax premium -- less than the 5,900 euros handed out for 2014 -- comes after VW also revealed huge bonuses for top executives last month, sparking a storm of criticism.

Those bosses' bonuses generated widespread resentment among employees, especially at a time of salary negotiations.

"Volkswagen staff provided very good work as a team, despite the difficult situation," said VW human resources chief Karlheinz Blessing in a statement.

"Their strong commitment deserved to be recognised," he added.

After criticism about the bosses' bonuses the automaker's supervisory board decided at the end of April to freeze 30 percent of the annual payouts for nine director-level executives.

The frozen amount will be paid out in three years if the company meets stock market targets.

The executives' bonuses sparked intense criticism both from the public and politicians, including German Finance Minister Wolfgang Schaeuble.

Volkswagen was forced to recall vehicles around the world last year after admitting it had installed so-called "defeat devices" aimed at cheating emissions tests into 11 million diesel engines.

The carmaker unveiled a loss of 1.58 billion euros after setting aside 16.2 billion euros in provisions to cover the potential fines, lawsuits and recall costs it foresees from the scandal.

It was the auto giant's first loss since 1993.

VW employs 600,000 people globally.