Toronto police say they've laid additional charges against a Taekwodo coach already accused of sexually assaulting some of his students.

Police say they arrested the coach in May 2018 and laid 13 charges against him, including six counts of sexual assault.

They say there are fresh allegations against him involving a former student.

Police allege he sexually assaulted a girl in both Toronto and London, Ont., between 2013 and 2015.

They say Shin Wook Lim surrendered to police earlier this week.

He's now facing four new charges - two counts each of sexual assault and sexual interference.