A former Team Sky medic has been warned that he will not be allowed to evade questions by MPs about a mystery padded package delivered during a race won by Sir Bradley Wiggins, despite pulling out of Wednesday's much-anticipated public investigation by the culture, media and sport select committee.

Dr Richard Freeman, who still works for British Cycling, would have faced a grilling about the package delivered at the the Critérium du Dauphiné race in France in 2011 - with former national coach Simon Cope, who couriered the package from Manchester, still scheduled to open the hearing at 2pm.

Freeman has told committee chairman Damian Collins that he is ill, though a spokesperson for the committee indicated on Tuesday that may be called when is well enough to attend and give the option of supplying written evidence. Committee member Julian Knight MP tweeted of Mr Freeman’s withdrawal: “News to me. I trust if true Dr Freeman recovers very soon and is then able to appear before us to answer important questions.”

Freeman was a medic at Team Sky (Getty)

The hearing has already been postponed one week after UK Anti-Doping (Ukad) chief executive, Nicole Sapstead, asked for more time because of a development in the agency’s five-month investigation into what it has described as “allegations of wrongdoing.”

The Team Sky head Sir Dave Brailsford has been under intense scrutiny since he told the parliamentary select committee in December he had been told by Freeman that the bag flown out the Criterium du Dauphiné contained a legal decongestant called Fluimucil. A full four months after launching its investigation into the package, UK Anti-Doping has still not been able to verify that claim.

Cope will be asked to explain why it needed a senior member of the British coaching team like him to deliver medication which is freely available in French chemists for a price of eight euros and which is next to useless, according to a French consumer group and several individuals who say they have used it.

He is expected to testify that he did not know what was in the package, given that Shane Sutton, Brailsford’s former right- hand man, has told MPs he authorised the package without knowing it was. Freeman, Sutton has said, asked him: “Do you know anyone coming down, logistics-wise? I need some stuff delivering. I didn't know what it was." The notion of Cope boarding a flight with a package he was so uncertain of is surprising, to say the least.

Wiggins won the 2011 Critérium du Dauphiné (Getty)

Sutton has said Wiggins needed the drug because he was struggling with his breathing and that Freeman administered it via a nebuliser. But MPs are determined to quiz Freeman on whether it was administered this way or the more common way - in combination with amino acids and vitamins – which aids recovery for endurance athletes.

Taking medicine this way - so-called IV recovery - is allowed out of competition, providing the athlete does not take more than 50 millilitres every six hours. It is not allowed in competition, however, and Wiggins would have been considered “in competition” until midnight that day.

Also to be questioned by MPs on Wednesday is Sapstead, who is likely to face some uncomfortable questions about how Ukad has conducted its investigation. British Cycling president, Bob Howden, promised the MPs in December “documentary evidence” would be provided to prove the package contained Fluimucil.

Documents show Freeman and other doctors ordered the drug and stored it at the National Cycling Centre, but there is no paperwork that definitively proves Fluimucil was in the package.