Services between King’s Cross, Walthamstow Central and Euston have been impacted by the delays since around 7am today (November 21).
It is unknown how long the disruption will last, however, there is good service on the rest of the line.
Elsewhere in London, on the Northern Line, severe delays were reported following an earlier points failure at Kennington.
Meanwhile, the Piccadilly Line also had severe delays eastbound between Acton Town and Cockfosters after an earlier customer incident.
However, all these services have since returned to normal.
A spokesperson for Transport for London said: “Victoria Line: Severe delays between King’s Cross and Walthamstow Central, northbound only, while we fix a faulty trains at Seven Sisters.
“Good service on the rest of the line.”