The council is sitting on emails between Mr Cull and the Ministry of Foreign Affairs and Trade discussing the Tibetan spiritual leader's visit to Dunedin.
The existence of the emails emerged last month, days after Mr Cull denied receiving outside advice on the visit of His Holiness.
Mfat staff would not release the correspondence at the time, citing the threat to New Zealand's international relations.
Dunedin City Council staff have been considering an Otago Daily Times official information request for the emails - and any other correspondence relating to the Dalai Lama's visit - for the past six weeks.
Late yesterday, on the same day as His Holiness arrived in Dunedin, the council finally declined to release the copies of Mr Cull's correspondence with Mfat officials.
Council staff cited ''an obligation of confidence'' and said publication would be likely to ''damage the public interest''.
Other emails were released showing early contact between the council, University of Otago, members of the Dhargyey Buddhist Centre in Dunedin and the Dalai Lama Visit Trust New Zealand.
The emails revealed little but showed discussions between the council and the trust organising the Dalai Lama's trip began in early August last year.
In April this year, Mr Cull confirmed he had declined an invitation to introduce the Dalai Lama at today's public talk in the Dunedin Town Hall, citing a prior engagement in Wellington.
The move prompted suggestions Mr Cull was putting Dunedin's economic links with Shanghai ahead of the Dalai Lama's trip.
Mr Cull later apologised after describing the Tibetan spiritual leader as ''a representative of a minority religious faith'', and confirmed Cr Jinty MacTavish would introduce His Holiness at today's town hall talk.
