A serial paedophile groped two girls aged just five and eight on a Tube platform after being released early from prison.
Stephen Lott's latest appalling sex assault happened at South Kensington station in July while the children were waiting for a District line train with their family.
Lott, of Collier Row, east London, denied sexually assaulting the girls but was found guilty at Blackfriars Crown Court last month and jailed for six months.
He was on early release having been jailed for seven years over a sex assault in 2011 – as well as a string of child sex offences in 2006 and 2007.
Det Const Allan McTaggart from British Transport Police said: “British Transport Police takes any sexual offences extremely seriously, particularly those involving children.
“Anyone who commits sexual offences of any kind on the Underground can expect to be arrested and convicted.”
The court was told how Lott, 37, moved in before the girls' family had a chance to step in, and brazenly groped his victims over their clothes.
But by chance two plain-clothes transport cops were watching and arrested Lott before he could leave the station.
His sentence will only begin once he has served five more years for his 2011 conviction.
