The chief lobbyist at Volkswagen has been suspended over allegations he knew about the German car industry testing the effects of diesel car emissions on monkeys and humans.

Thomas Steg, head of group external relations and sustainability, offered to step down this week while VW launches an investigation into the latest sorry chapter of Dieselgate.

The tests were conducted by the Lovelace Respiratory Research Institute in Albuquerque, New Mexico in 2014 and were conducted on behalf of the now-defunct European Research Group on Environment and Health in the Transport Sector (EUGT), a body that was funded by Volkswagen, Daimler and BMW.

According to the New York Times, which first uncovered the claims, the monkeys were exposed to exhaust fumes from older, more polluting vehicles as well as more modern, cleaner cars to test the effectiveness of exhaust after-treatment.

It claimed 10 monkeys were locked in airtight chambers and allowed to watch cartoons while they breathed the exhaust fumes from a VW Beetle. And it has been reported in Germany that 25 people were given doses of diesel fumes for several hours at a time in a study conducted at Aachen University in 2012; these tests were also sponsored by EUGT.

Car makers react to monkey diesel emissions tests

All three of the German car makers have expressed disgust at the allegations and have been quick to distance themselves from them. VW said: ‘We believe that the scientific method chosen at the time was wrong’ while BMW made clear ‘it does not carry out any animal experiments’ and that ‘the BMW Group in no way influenced the design or methodology of studies carried out on behalf of the EUGT.’

Daimler meanwhile called the study ‘superfluous and repulsive.’ The EUGT was founded in 2007 and disbanded in June 2017.

Piling more pressure on the car industry

The ethics of the monkey testing saga have rocked an automotive sector only just recovering from the so-called Dieselgate scandal of 2015. VW was found to have systematically cheated emissions tests in the US and Europe by using 'cheat devices' so vehicles could detect when they were in a lab and when they were on a real road, trimming exhaust pollution signficantly to score better in tests.

Volkswagen has set aside more than €30 billion to pay fines, recalls and other costs arising, forced sweeping changes in its management and realigned its future strategy around electric cars, as it accelerates away from fossil fuels.

How dieselgate unfolded: a look back at the emissions crisis of 2015

It's been a grim few months for Volkswagen, which saw sales plunge by 20% in November 2015, according to Society of Motor Manufacturers and Traders (SMMT) figures. The fall came as other car makers celebrated a rise in a growing market.

Volkswagen has became embroiled in a fresh raft of emissions 'defeat device' allegations, with the US Environmental Protection Agency alleging that 3.0-litre diesel engines in a variety of current VW, Audi and Porsche are fitted with software capping their nitrogen oxide (NOx) emissions during testing but allowing levels up to nine times greater during ordinary driving. What's more, VW has also admitted it has uncovered 'irregularities' in how it has measured CO2 levels in around 800,000 VWs, Audis, Skodas and Seats in Europe, a development which could cost the company a further €2 billion (£1.4bn) to rectify.

EA288 EU5 and EU6 engines declared defeat device-free

Volkswagen has issued a statement declaring EU5 and EU6 versions of the EA288 engine family free from 'improper defeat device' software ‘as defined in law’. This means that VW believes these engines, including those used by Audi, Seat and Skoda, comply with European legislation regarding emissions. However, VW has also confirmed that it is still investigating whether variants of these engines sold outside the European Union conform to other regional emissions requirements.

The EA288 engine family is an evolution of the older EA189 engine family at the centre of the VW ‘dieselgate’ emissions scandal. Work continues on technical solutions to vehicles affected by the controversy, and Volkswagen has reiterated that the necessary corrective measures will begin rolling out in January 2016 – though exact technical details remain unclear.

VW will now fast-track new clean tech

The former chief of Skoda, Winfried Vahland who was poised to run Volkswagen USA, has quit the VW group because of 'differing views on the organisation of the new group region' in a planned shake-up of how the car making giant is structured. It's just one of a series of developments in the VW emissions scandal, as the company cuts €1 billion a year from its R&D budget.

German authorities have now ordered the car maker to recall 2.4 million cars to fix the defective software in affected cars, rather than do it in a voluntary fashion (as has been mooted in the UK). And, separately, Italian police have raided VW offices in Verona and Lamborghini HQ in Bologna searching for any evidence of commercial fraud, according to Italian media reports.

And it's becoming clearer what effect the new austerity era in Wolfsburg will have: VW has pledged that the next-generation Phaeton will switch to become an electric limousine, it's fast-tracking hyper-clean diesel technology and it will develop a new scalable electric architecture dubbed MEB to underpin a new generation of EVs with projected ranges of between 150-300 miles.

The VW emissions crisis in the UK

The UK boss of Volkswagen, Paul Willis (below), has been hauled in front of MPs and admitted that 400,000 British cars will need physical engine modifications to remedy the 'defeat device' emissions cheat software. The company has already warned that the fix won't get underway until January 2016, and it could take another year before all cars are sorted.