Blackwall Tunnel was closed in the early hours of Sunday morning when a man was spotted jogging through the link.
The man, in a light-coloured shirt and jeans, was caught on CCTV cameras jogging through the northbound bore at 2.46am. There are no walkways and the tunnel is exceptional narrow in places.
The tunnel, which is managed by Transport for London, was shut for 10 minutes and no arrests were made.
This isn’t the first time that the tunnel has been brought to a halt by someone seeking a quick short-cut. The tunnel was closed in July last year when a woman was spotted carrying her shopping through to North Greenwich.
Pedestrians have been banned from using the tunnel since 1969 and pedestrians are encouraged to make use of the Greenwich and Woolwich foot tunnels if the Woolwich ferry isn’t working.
The delay comes just days after the tunnel was closed for hours causing massive tailbacks when a lorry leaked hydraulic fluid on the surface, which had to be replaced at a cost of £150,000.