The Eurostar train was halted in the tunnel for about 30 minutes
Channel Tunnel passengers have been warned to expect further delays to Eurostar services after an early morning train suffered a power problem.
The London to Paris service, which left St Pancras at 0655 BST, was halted in the tunnel for about half an hour.
A Eurostar spokesman said there had been a technical fault with the pantograph - the device which draws power from the overhead lines.
The train was able to travel to Calais Frethun, where it was being inspected.
The spokesman said the incident was likely to lead to delays of up to two hours to services, which have only just returned to 50% of normal levels following the fire at the French end of the tunnel on 11 September.
On Monday, a 10.6-mile (17km) section of the north tunnel reopened.
Thirty two people on a lorry shuttle service had to be led to safety after the fire broke out.
Fourteen suffered minor injuries, including smoke inhalation.
The cause of the blaze has not yet been identified but French officials say a lorry carrying chemicals, which is understood to have overturned, was close to the seat of the fire.