Team Astana have been temporarily suspended by the Movement for Credible Cycling (MPCC) after allowing Lars Boom to start the Tour de France despite a pre-race test showing that the Dutchman had abnormally low cortisol levels.

Under article 9 of the MPCC regulations, riders who are shown to have a low level of cortisol are required to refrain from competition for an eight-day period. Low cortisol levels can indicate illness, or the use of the steroid cortisone, though there is no evidence that Boom has committed any doping violation.

>>> Lars Boom cortisol case: what you need to know

A statement from the organisation read, “In the wake of the choice of Astana to allow Lars Boom to take the start of the Tour de France and thus not to respect article 9 of the MPCC’s rules, unanimously the board of directors of MPCC take notice of this decision and temporarily suspend Team Astana, until the next meeting of the board of directors according to its statute.”

Boom was tested last Thursday, two days before the start of the Tour. The results came back after Friday’s manager’s meeting, after which UCI rules prevent squad changes, which left Astana facing the prospect of starting the race a man down.

Rather than begin the defence of Vincenzo Nibali’s title with only eight riders, the team decided to start with Boom, leaving them to face off against the MPCC.

“Team medical staff have advised that Boom’s low cortisol level is the consequence of a long-standing and well-known application of anti-asthma therapy and that there is no danger to the rider’s health and safety in starting the 2015 Tour de France,” read a statement issued by Astana on the eve of the race.

Astana’s insistence on racing Boom, effectively ignoring the MPCC, is another blow for the organisation. As of now, less than half of the WorldTour teams are members of the organisation.

Last month Dutch squad LottoNL-Jumbo withdrew from the MPCC, questioning the accuracy of testing after George Bennett was forced to miss the Giro d’Italia due to low cortisol levels. In 2013 Theo Bos was withheld from competing in the Vuelta a España for the same reason.

Italian squads Lampre-Merida and Bardiani-CSF have also left the MPCC in recent months, with an unnamed Bardiani rider also falling foul of the cortisol test prior to the Giro d’Italia.

Watch Cycling Weekly’s guide to the cobbled stage four of the Tour de France