When does The No. 1 Ladies' Detective Agency return?

The No. 1 Ladies' Detective Agency is a television comedy-drama series based on the novels of the same name by Alexander McCall Smith. The novels focus on the story of a detective agency opened by Mma Ramotswe and her courtship with the mechanic Mr. J. L. Matekoni. The programme began with a feature-length television film, broadcast in the UK on the BBC on 23 March 2008. A six-episode series was ordered in November 2008 and the BBC began broadcasting it on 15 March 2009. HBO announced in summer 2011 that the series might continue as two or more standalone films. It was cancelled after one season despite positive reviews.