The co-chairman of the Greens in the European Parliament, Daniel Cohn-Bendit, today likened the resignation saga of John Dalli to a "detective novel", citing the influence of big tobacco and its "borderline" tactics behind the former commissioner's fall from grace.

"This is a very strange case which for the moment, doesn't seem clear to us," Cohn-Bendit said of the OLAF investigation into John Dalli, which the Green MEP said should be made public.

But the MEP also said that Commission president José Barroso will have some questions to answer from the Greens in the next meeting of the European Parliament, to explain Dalli's resignation. "We would also like to know why Mr Barroso is blocking the directive on tobacco and why he has been doing that for several months inside the Commission," Cohn-Bendit said.

Dalli resigned over allegations that there was circumstantial evidence that he was aware that a former canvasser had asked snus producers Swedish Match for €60 million to reverse a ban on the sale of the snus in the EU, in Dalli's upcoming review of the Tobacco Products Directive.

"You can say it's like a detective novel, like an investigation. When you take on big tobacco everything is possible - you know, large tobacco companies in the United States have practices which are more borderline, so in this case was Dalli pushed into a trap? Who is behind this trap? Or was he working alone? Both options are open at the moment.

"The story is very unclear and we will prepare our file with statements from various people and asking for more transparency from the Commission."

The European Commission will not hold any further discussion on the health and consumer policy portfolio previously held by John Dall until the formal appointment of Tonio Borg to the position, EC president José Barroso told MEPs in a letter.

Barroso, who is said by Dalli to have asked him to resign, told MEPs in a letter that he was currently discussing with vice-president Maros Sefcovic the "best way forward on the revision of the Tobacco Products Directive".

Concretely, this is likely to postpone to next year legislative proposals on tobacco products since it will not be until next month that Tonio Borg will be grilled by MEPs on his competence on health and consumer policy.

The Tobacco Products Directive which Dalli was reviewing including new, stricter packaging conditions that covered up to 75% of the surface area of cigarette packs with health warnings, as well as a complete ban on smokeless tobacco.

A day after Dalli's resignation, MEPs from the Committee on the Environment, Public Health and Food Safety (ENVI) called on Barroso to give them his assurance that the work on the tobacco directive will not be disrupted following Dalli's resignation, and that it will "contain strong public health measures, which will not be watered down and that you will be asking Commissioner Sefcovic to issue a clear timetable for the directive to be adopted by college by the end of the year."

Dalli himself warned the MEPs of the risks of further delays. In a letter dated 22 October, he explained that the proposal had already been seriously delayed compared to what was planned. According to Dalli, the proposal, which his services finalised in late February 2012, "was ready to be submitted to interservice consultation in late August 2012," but "this was stopped by the secretary-general and the legal services".

The consultation should have been re-launched in early October but it has once again been postponed to 22 October. "Now the commissioner is removed and the launching of the directive will probably be postponed again. If it is not launched in time for its conclusion during the term of this legislature, the tobacco directive will be derailed. I would like to ask you not to let this happen. Please insist with the Commission that this directive is launched as planned so that thousands of lives can be saved," the former commissioner said.