document: The health watchdog said it had taken "urgent action" after an unannounced inspection at Pro Medicus in Harpenden.
  It has declined to say why it took the action, stating its reasons will be revealed in a report being published at a later date.
  Pro Medicus director Stephen Burton said it had taken "robust action".
  The CQC said it carried out an unannounced inspection on 3 and 4 August and chose to take "urgent action to temporarily suspend the registration of this provider".
  It said that the suspension was due to last until 18 September "whilst they take action to address the concerns we have".
  The CQC said the provider could not undertake any of its regulated work while it was under suspension.
  Pro Medicus has more than 30 years' experience providing independent ambulances, medical supervision and first aid training courses throughout the UK.
  Its website claims its clients include NHS trusts, Stevenage Football Club, Cambridge United Football Club and Saracens Rugby Club.
  The watchdog gave the company a clean bill of health in its last inspection in November 2013.
  Mr Burton declined to say what the issues were about, adding: "We've taken advice from the CQC. A number of things were highlighted - we're not denying what they've said need addressing.
  "We've taken robust action and we've got staff in at the moment going through everything and we're updating lots of things.
  "As far as we're concerned we've always had a good name. We're going to bring it up to scratch and hopefully in the next few weeks everything will be in place."
summary: A private ambulance firm based in Hertfordshire has had its registration temporarily suspended due to "concerns" by the Care Quality Commission (CQC).